Electrochromic lithium nickel group 6 mixed metal oxides

ABSTRACT

Multi-layer electrochromic structures comprising an anodic electrochromic layer comprising a lithium nickel oxide composition on a first substrate, the anodic electrochromic layer comprising lithium, nickel and a Group 6 metal selected from molybdenum, tungsten and a combination thereof, wherein (i) the atomic ratio of lithium to the combined amount of nickel, molybdenum, and tungsten in the anodic electrochromic layer is at least 0.4:1, respectively, (ii) the atomic ratio of the combined amount of molybdenum and tungsten to the combined amount of nickel, molybdenum and tungsten in the anodic electrochromic layer is at least about 0.025:1, respectively, and (iii) the anodic electrochromic layer exhibits an interplanar distance (d-spacing) of at least 2.5 Å as measured by X-ray diffraction (XRD), comprises at least 0.05 wt. % carbon, and/or has a coloration efficiency absolute value of at least 19 cm2/C.

FIELD OF THE INVENTION

The present invention generally relates to anodic electrochromicmaterial comprising lithium, nickel and a Group 6 metal selected frommolybdenum and tungsten, and in one embodiment, lithium nickel oxidefilms comprising molybdenum and/or tungsten for switchableelectrochromic multi-layer devices.

BACKGROUND OF THE INVENTION

Commercial switchable glazing devices, also commonly known as smartwindows and electrochromic window devices, are well known for use asmirrors in motor vehicles, aircraft window assemblies, sunroofs,skylights, and architectural windows. Such devices may comprise, forexample, active inorganic electrochromic layers, organic electrochromiclayers, inorganic ion-conducting layers, organic ion-conducting layersand hybrids of these sandwiched between two conducting layers. When avoltage is applied across these conducting layers the optical propertiesof a layer or layers in between change. Such optical property changestypically include a modulation of the transmissivity of the visible orthe solar sub-portion of the electromagnetic spectrum. For convenience,the two optical states will be referred to as a bleached state and adarkened state in the following discussion, but it should be understoodthat these are merely examples and relative terms (i.e., a first one ofthe two states is more transmissive or “more bleached” than the otherstate and the other of the two states is less transmissive or “moredarkened” than the first state) and that there could be a set ofbleached and darkened states between the most transmissive state and theleast transmissive state that are attainable for a specificelectrochromic device; for example, it is feasible to switch betweenintermediate bleached and darkened states in such a set.

The broad adoption of electrochromic window devices in the constructionand automotive industries will require a ready supply of low cost,aesthetically appealing, durable products in large area formats.Electrochromic window devices based on metal oxides represent the mostpromising technology for these needs. Typically, such devices comprisetwo electrochromic materials (a cathode and an anode) separated by anion-conducting film and sandwiched between two transparent conductingoxide (TCO) layers. In operation, a voltage is applied across the devicethat causes current to flow in the external circuit, oxidation andreduction of the electrode materials and, to maintain charge balance,mobile cations to enter or leave the electrodes. This facileelectrochemical process causes the window to reversibly change from amore bleached (e.g., a relatively greater optical transmissivity) to amore darkened state (e.g., a relatively lesser optical transmissivity).

TCO materials typically used in electrochromic windows such as FTO andITO react with lithium at voltages below ˜1V vs. Li/Li+, lowering theirelectrical performance and darkening the material. Electrolytestypically incorporated into the ion conductor, or the presence of wateror protic impurities, have voltage stability windows between ˜1 and ˜4.5V vs. Li/Li+. Therefore, it is beneficial to use electrode materialsthat undergo redox events within these limits. For example, tungstenoxide (WO3) is a well known cathodic electrochromic material that isbleached at ˜3.2 V vs. Li/Li+ and darkens upon reduction, typically to˜2.3 V vs. Li/Li+. Consequently, electrochromic devices comprising atungsten oxide cathode are common.

Certain nickel oxide and hydroxide based materials darken anodically toproduce a darkened state transmission spectrum that is complementary tolithiated WO₃ and it is a popular target to partner WO₃ inelectrochromic windows. Certain methods for the preparation of lithiumnickel oxide films (LiNiOx) have been reported in the literature. Theseinclude sputter methods (see, e.g., Rubin et. al. Solar Energy Materialsand Solar Cells 54; 998 59-66) and solution methods (see, e.g., Sveglet. al., Solar Energy V 68, 6, 523-540, 2000). In both cases the filmsexhibit high area charge capacity (>20 mC/cm²), with bleached statevoltages of ˜1.5V. This bleached state voltage is relatively close tothe reaction potential of lithium with typical TCO materials, the lowervoltage limit of common electrolytes and the reaction potential requiredto over-reduce lithiated nickel oxides to nickel metal, a cathodicelectrochromic reaction. The proximity of the bleached state voltage tosuch degrading mechanisms presents significant device control issues:methods will be required to consistently drive the device to thebleached state without driving the anode into damaging voltage regimesaccommodating, for example, issues such as local electrodeinhomogeneity. Furthermore, the bleached state lithiated nickel oxidecannot typically be handled in air without the material performancedegrading. The lack of air stability of the bleached state of un-dopedlithium nickel oxide films is demonstrated in the examples section ofthis invention where lithium nickel oxide films were prepared usingliquid mixtures of lithium and nickel salts to produce, after thermalprocessing, films in their darkened state. Upon electrochemical orchemical reduction to their lithiated forms in an inert atmospherebleached state films were produced but upon exposure to air in thisbleached state they quickly lose the reversible electrochromicproperties.

Examples of sputter coated lithiated nickel oxides that contain a secondmetal have been reported. For example, U.S. Pat. No. 6,859,297 B2describes the lithiation (and bleaching) of mixed nickel oxide filmsthat contain Ta and W in appreciable quantities. The material wasprepared by a two step process, the first step being a vacuumco-sputtering process to produce a mixed Ta/Ni oxide film and secondelectrochemical lithiation step to produce a material in its bleachedstate. The Ta-containing oxide films are characterized extensively andhave no long range order of evidence of crystallinity by XRD and,required handling in a controlled atmosphere to preclude their exposureto water and oxygen.

A wide range of structures derive from metal occupation of theoctahedral and tetrahedral sites within close packed anion arrays. Insuch arrays, there are equal numbers of octahedral sites as anions andtwice as many tetrahedral sites as anions. The term “rock salt” as usedherein describes a cubic structure in which metal cations (“M”) occupyall of the octahedral sites within a close packed anion array, resultingin the stoichiometry MO. Furthermore, the metals are indistinguishablefrom one another regardless of whether the metals are the same elementor a random distribution of different elements. In the specific case ofNiO, for example, the cubic rock salt unit cell has a ˜4.2 Å and alargest d-spacing of ˜2.4 Å. In the case where there is more than onetype of metal, different structures are created depending upon how andif the metals order themselves over the octahedral and tetrahedralholes. The case of Li_(x)Ni_(1-x)O is instructive: for all values of x,the oxygen anions are close packed and the metals are arranged on theoctahedral sites. For values of x less than ˜0.3, the lithium and nickelcations are randomly arranged; for values of x greater than 0.3, themetals segregate to create nickel-rich and lithium-rich layers, creatinglayered structures with hexagonal symmetry. The end member,Li_(1/2)Ni_(1/2)O (equivalently, LiNiO₂) is formed from alternate layersof —Ni—O—Li—O— with a hexagonal unit cell (a=2.9, c=14.2 Å) and alargest d-spacing of ˜4.7 Å. The voltage associated with the lithiumintercalation events is above 3V vs. Li/Li+.

Even though all of the octahedral sites in LiNiO₂ are full, additionallithium can be inserted into the material, forming Li_(1-x)NiO₂. Theadditional lithium necessarily occupies sites in close proximity toother cations with less shielding from the anion array. Thus, theinsertion of this additional lithium occurs at lower voltages, <2V vs.Li/Li+ for bulk phase materials.

Other phases that are possible from metal occupation of sites withinclose-packed oxygen arrays include the orthorhombic phasesLi_(1/2)Ni_(1/3)Ta_(1/6)O and Li_(1/2)Ni_(1/3)Nb_(1/6)O in which the Nbor Ta segregate to one set of octahedral sites and the Ni and Li aremixed on the remaining sites. Further examples are the spinel phasesincluding Li_(1/4)Mn_(3/8)Ni_(1/8)O in which Mn and Ni occupy theoctahedral sites and Li occupies ¼ of the tetrahedral sites.

A collective signature of all of the phases described above are theclose packed layers. In the rock salt structure, these give rise to asingle diffraction reflection at ˜2.4 Å, labeled as the (111)reflection. This is the largest symmetry allowed d-spacing in the rocksalt structure. The second largest d-spacing allowed in the rock saltstructure is the (200) peak whose d-spacing is ˜2.1 Å. In lower symmetrystructures such as Li_(1/2)Ni_(1/2)O and Li_(1/2)Ni_(1/3)Ta_(1/6)O,reflections equivalent to the rock salt (111) and (200) reflections areobserved at approximately the same d-spacing but are labeled differentlyand may be split into multiple peaks. For example, in the hexagonal,layered material the rock salt (111) reflection splits into tworeflections, the (006) and the (102) peak, both of which occur at ˜2.4 Åand the rock salt (200) peak becomes the (104) peak, whose d-spacing isalso 2.1 Å. A clear signature that an ordered metal sub-lattice existswithin a material giving rise to structures such as Li_(1/2)Ni_(1/2)O,Li_(1/2)Ni_(1/3)Nb_(1/6)O, and Li_(1/4)Mn_(3/8)Ni_(1/8)O is the presenceof reflections with d-spacings greater than 2.4 Å (Table 1).

TABLE 1 Largest d-spacing (Å) and associated hkl of example materialsderived from metals within octahedral and/or tetrahedral sites createdby close packed oxygen arrays Largest Composition Structure Noted-spacing (Å) hkl NiO rock salt 2.4 (111) Li_(0.1)Ni_(0.9)O rock salt,Li and Ni randomly 2.4 (111) arranged Li_(1/2)Ni_(1/2)O Hexagonal, Liand Ni ordered 4.7 (003) into layers Li_(1/2)Ni_(1/3)Ta_(1/6)OOrthorhombic, Ta and Li/Ni 4.7 (111) ordered Li_(1/4)Mn_(3/8)Ni_(1/8)OCubic, Ni/Mn in octahedral 4.7 (111) sites; Li in tetrahedral sites

Although a range of electrochromic anodic materials have been proposeddate, there is a need for anode films that can be prepared by simplesingle-step deposition processes to produce EC anodes with improvedthermal stability, high optical clarity in their as-deposited states,and that can be tuned via composition and film thickness to adopt a widevariety of area charge capacities and optical switching properties.

SUMMARY OF THE INVENTION

Among the various aspects of the present invention is the provision ofnovel anodic electrochromic films and the provision of articlescomprising such compositions.

Briefly, therefore, one aspect of the present invention is a multi-layerelectrochromic structure comprising an anodic electrochromic layer on asubstrate, the anodic electrochromic layer comprising a lithium nickeloxide composition wherein the bulk constituent of the anodicelectrochromic layer is a phase incorporating oxygen and one or both ofmolybdenum and tungsten in addition to lithium and nickel. The presenceof Mo and/or W in the phase acts to increase the bleached state voltageof the material and lower the volumetric capacity by reducing the amountof lithium required to reduce nickel to Ni(II).

A further aspect of the present invention is a multi-layerelectrochromic structure comprising an anodic electrochromic layer on afirst substrate wherein the anodic electrochromic layer comprises alithium nickel oxide composition, is characterized by a largestd-spacing of at least 2.5 Å and comprises lithium, nickel, and at leastone of molybdenum and tungsten.

A further aspect of the present invention is a multi-layerelectrochromic structure comprising an anodic electrochromic layer on afirst substrate, the anodic electrochromic layer containing lithium,nickel, and at least one of molybdenum and tungsten, wherein (i) theatomic ratio of lithium to the combined amount of nickel, molybdenum andtungsten in the anodic electrochromic layer is at least 0.4:1,respectively, (ii) the atomic ratio of the combined amount of molybdenumand tungsten to the combined amount of nickel, molybdenum and tungstenin the anodic electrochromic layer is at least about 0.025:1,respectively, and (iii) the anodic electrochromic layer exhibits aninterplanar distance (d-spacing) of at least 2.5 Å as measured by XRD.

A further aspect of the present invention is a multi-layerelectrochromic structure comprising an anodic electrochromic layer on afirst substrate, the anodic electrochromic layer containing lithium,nickel, and at least one of molybdenum and tungsten, wherein (i) theatomic ratio of lithium to the combined amount of nickel, molybdenum andtungsten in the anodic electrochromic layer is at least 0.4:1,respectively, (ii) the atomic ratio of the combined amount of molybdenumand tungsten to the combined amount of nickel, molybdenum and tungstenin the anodic electrochromic layer is at least about 0.025:1,respectively, and (iii) the anodic electrochromic layer comprises atleast 0.05 wt. % carbon.

A further aspect of the present invention is a multi-layerelectrochromic structure comprising an anodic electrochromic layer on afirst substrate, the anodic electrochromic layer containing lithium,nickel, and at least one of molybdenum and tungsten, wherein (i) theatomic ratio of lithium to the combined amount of nickel, molybdenum andtungsten in the anodic electrochromic layer is at least 0.4:1,respectively, (ii) the atomic ratio of the combined amount of molybdenumand tungsten to the combined amount of nickel, molybdenum and tungstenin the anodic electrochromic layer is at least about 0.025:1,respectively, and (iii) the anodic electrochromic layer has a colorationefficiency absolute value of at least 19 cm2/C.

A further aspect of the present invention is a multi-layerelectrochromic structure comprising an anodic electrochromic layer on afirst substrate wherein the anodic electrochromic layer compriseslithium, nickel, and at least one of molybdenum and tungsten, and theatomic ratio of the amount of lithium to the combined amount of nickel,molybdenum and tungsten in the lithium nickel oxide composition is lessthan 1.75:1, respectively, when the lithium nickel oxide composition isin its fully bleached state.

A further aspect of the present invention is an electrochromic structurecomprising a first substrate and a second substrate, a first and asecond electrically conductive layer, a cathode layer, an anodicelectrochromic layer, and an ion conductor layer, wherein the firstelectrically conductive layer is between the first substrate and theanodic electrochromic layer, the anodic electrochromic layer is betweenthe first electrically conductive layer and the ion conductor layer, thesecond electrically conductive layer is between the cathode layer andthe second substrate, the cathode layer is between the secondelectrically conductive layer and the ion conductor layer, and the ionconductor layer is between the cathode layer and the anodicelectrochromic layer. The anodic electrochromic layer comprises lithium,nickel, and at least one Group 6 metal selected from the groupconsisting of molybdenum and tungsten wherein the atomic ratio of theamount of lithium to the combined amount of nickel, molybdenum andtungsten in the anodic electrochromic layer is less than 1.75:1,respectively, when the anodic electrochromic layer is in its fullybleached state.

A further aspect of the present invention is an electrochromic structurecomprising a first substrate and a second substrate, a first and asecond electrically conductive layer, a cathode layer, an anodicelectrochromic layer, and an ion conductor layer, wherein the firstelectrically conductive layer is between the first substrate and theanodic electrochromic layer, the anodic electrochromic layer is betweenthe first electrically conductive layer and the ion conductor layer, thesecond electrically conductive layer is between the cathode layer andthe second substrate, the cathode layer is between the secondelectrically conductive layer and the ion conductor layer, and the ionconductor layer is between the cathode layer and the anodicelectrochromic layer. The anodic electrochromic layer comprises alithium nickel oxide composition and comprises lithium, nickel, and atleast one Group 6 metal selected from the group consisting of molybdenumand tungsten wherein the anodic electrochromic layer exhibits long rangeordering and a largest d-spacing of at least 2.5 Å.

A further aspect of the present invention is a process for forming amulti-layer electrochromic structure. The process comprises depositing afilm of a liquid mixture onto a surface of a substrate and treating thedeposited film to form an anodic electrochromic layer composition on thesurface of the substrate wherein the liquid mixture comprises at leastone Group 6 metal selected from the group consisting of molybdenum andtungsten.

A further aspect of the present invention is a process for preparing anelectrochromic structure comprising a first and a second substrate, afirst and a second electrically conductive layer, a cathode layer, ananodic electrochromic layer and an ion conductor layer wherein the firstelectrically conductive layer is between the first substrate and theanodic electrochromic layer, the anodic electrochromic layer is betweenthe first electrically conductive layer and the ion conductor layer, thesecond electrically conductive layer is between the cathode layer andthe second substrate, the cathode layer is between the secondelectrically conductive layer and the ion conductor layer, and the ionconductor layer is between the cathode layer and the anodicelectrochromic layer. The process comprises depositing a liquid mixturecomprising lithium, nickel and at least one Group 6 metal selected fromthe group consisting of molybdenum and tungsten onto a surface to form adeposited film, and treating the deposited film to form the anodicelectrochromic layer comprising lithium nickel oxide.

Other objects and features will be in part apparent and in part pointedout hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-section of a multi-layer electrochromicstructure comprising an anodic electrochromic layer of the presentinvention.

FIG. 2 is a schematic cross-section of an alternative embodiment of amulti-layer electrochromic structure comprising an anodic electrochromiclayer of the present invention.

FIG. 3 is a thin-film XRD pattern of an anodic electrochromic filmcoated on a FTO substrate, measured with the wavelength CuKα=1.540695 Åas described more fully in Example 2.

FIG. 4 is a plot of the cyclovoltammetry traces of anodic electrochromicfilms coated on a FTO substrate in 1 M LiClO₄ in propylene carbonateelectrolyte using a scan rate of 10 mV/s, as described more fully inExample 2.

FIG. 5 is a plot of the cyclovoltammetry traces of lithium nickel oxide(labeled LiNiO₂) film coated on a FTO substrate and itschemically-reduced film (labeled Li₂NiO₂) represented in green and redlines, respectively, measured in 1 M LiClO₄ in propylene carbonateelectrolyte, as more fully described in Example 3.

FIG. 6 is a thin-film XRD pattern of Li₁W_(0.25)Ni_(0.75)O_(z) anodicelectrochromic film coated on a FTO substrate, and measured with thewavelength CuKα=1.540695 Å as more fully described in Example 12.

Corresponding reference characters indicate corresponding partsthroughout the drawings. Additionally, relative thicknesses of thelayers in the different figures do not represent the true relationshipin dimensions. For example, the substrates are typically much thickerthan the other layers. The figures are drawn only for the purpose toillustrate connection principles, not to give any dimensionalinformation.

ABBREVIATIONS AND DEFINITIONS

The following definitions and methods are provided to better define thepresent invention and to guide those of ordinary skill in the art in thepractice of the present invention. Unless otherwise noted, terms are tobe understood according to conventional usage by those of ordinary skillin the relevant art.

Unless otherwise indicated, the alkyl groups described herein arepreferably lower alkyl containing from one to eight carbon atoms in theprincipal chain and up to 20 carbon atoms. They may be linear orbranched chain or cyclic and include methyl, ethyl, propyl, isopropyl,butyl, hexyl, cyclohexyl and the like.

The terms “amine” or “amino,” as used herein alone or as part of anothergroup, represents a group of formula —N(R⁸)(R⁹), wherein R⁸ and R⁹ areindependently hydrogen, hydrocarbyl, substituted hydrocarbyl, silyl, orR⁸ and R⁹ taken together form a substituted or unsubstituted cyclic orpolycyclic moiety, each as defined in connection with such term,typically having from 3 to 8 atoms in the ring. “Substituted amine,” forexample, refers to a group of formula —N(R⁸)(R⁹), wherein at least oneof R⁸ and R⁹ are other than hydrogen. “Unsubstituted amine,” forexample, refers to a group of formula —N(R⁸)(R⁹), wherein R⁸ and R⁹ areboth hydrogen.

The term “alkoxide” as used herein refers to a deprotonated alcohol andis typically used to describe a metal complex of the form M¹-OR where M¹is a metal.

There term “amide” as used herein in connection with a metal complexrefers to a metal complex of the form M¹-N(R⁸)(R⁹) where M¹ is a metal.

The terms “aryl” as used herein alone or as part of another group denoteoptionally substituted homocyclic aromatic groups, preferably monocyclicor bicyclic groups containing from 6 to 12 carbons in the ring portion,such as phenyl, biphenyl, naphthyl, substituted phenyl, substitutedbiphenyl or substituted naphthyl. Phenyl and substituted phenyl are themore preferred aryl.

The terms “anodic electrochromic layer” and “anodic electrochromicmaterial” refer to an electrode layer or electrode material,respectively, that upon the removal of ions and electrons becomes lesstransmissive to electromagnetic radiation.

The term “bleach” refers to the transition of an electrochromic materialfrom a first optical state to a second optical state wherein the firstoptical state is less transmissive than the second optical state.

The term “bleached state stabilizing element” as used herein means anelement that acts to increase the bleached state voltage of lithiumnickel oxide without adversely affecting the transmissivity of its fullybleached state, such as by decreasing the transmissivity of the fullybleached state or by resulting in a shift in the color coordinates ofthe fully bleached state, such as the creation of a yellow or brown hueto said fully bleached state. In general, bleached state stabilizingelements are those elements that readily form as colorless or lightlycolored oxides solids in their highest oxidation state (i.e., formallyd0), and where the highest oxidation state is 3+ or greater.

The term “bleached state voltage” refers to the open circuit voltage(V^(oc)) of the anodic electrochromic layer versus Li/Li+ in anelectrochemical cell in a propylene carbonate solution containing 1Mlithium perchlorate when the transmissivity of said layer is at 95% ofits “fully bleached state” transmissivity.

The terms “cathodic electrochromic layer” and “cathodic electrochromicmaterial” refer to an electrode layer or electrode material,respectively, that upon the insertion of ions and electrons becomes lesstransmissive to electromagnetic radiation.

The term “coloration efficiency” or “CE” refers to a property of anelectrochromic layer that quantifies how a layer's optical densitychanges as a function of its state of charge. CE can vary significantlydepending on layer preparation due to differences in structure, materialphases, and/or composition. These differences affect the probability ofelectronic transitions that are manifest as color. As such, CE is asensitive and quantitative descriptor of an electrochromic layerencompassing the ensemble of the identity of the redox centers, theirlocal environments, and their relative ratios. CE is calculated from theratio of the change in optical absorbance to the amount of chargedensity passed. In the absence of significant changes in reflectivity,this wavelength dependent property can be measured over a transition ofinterest using the following equation:

${CE}_{A} = \frac{\log_{sc}\left( \frac{T_{ini}}{T_{final}} \right)}{Q_{A}}$where Q_(A) is the charge per area passed, T_(ini) is the initialtransmission, and T_(final) is the final transmission. For anodicallycoloring layers this value is negative, and may also be stated inabsolute (non-negative) value. A simple electrooptical setup thatsimultaneously measures transmission and charge can be used to calculateCE. Alternatively, the end transmission states can be measured ex situbefore and after electrical switching. CE is sometimes alternativelyreported on a natural log basis, in which case the reported values areapproximately 2.3 times larger.

The term “darken” refers to the transition of an electrochromic materialfrom a first optical state to a second optical state wherein the firstoptical state is more transmissive than the second optical state.

The term “electrochromic material” refers to materials that change intransmissivity to electromagnetic radiation, reversibly, as a result ofthe insertion or extraction of ions and electrons. For example, anelectrochromic material may change between a colored, translucent stateand a transparent state.

The term “electrochromic layer” refers to a layer comprising anelectrochromic material.

The term “electrode layer” refers to a layer capable of conducting ionsas well as electrons. The electrode layer contains a species that can bereduced when ions are inserted into the material and contains a speciesthat can be oxidized when ions are extracted from the layer. This changein oxidation state of a species in the electrode layer is responsiblefor the change in optical properties in the device.

The term “electrical potential,” or simply “potential,” refers to thevoltage occurring across a device comprising an electrode/ionconductor/electrode assembly.

The term “electrochemically and optically matched” (EOM) refers to a setof cathode and anode electrochromic films with similar chargecapacities, that are in their complimentary optical states (e.g., bothin their bleached state, or both in their darkened state or both in anintermediate state of coloration) such that when joined together by asuitable ion-conducting and electrically insulating layer, a functionalelectrochromic device is formed that shows reversible switching behaviorand high switching currents

The term “fully bleached state” as used in connection with an anodicelectrochromic material refers to the state of maximum transmissivity ofan anodic electrochromic layer in an electrochemical cell at or above1.5V versus Li/Li+ in a propylene carbonate solution containing 1 Mlithium perchlorate at 25° C. (under anhydrous conditions and in an Aratmosphere).

The terms “halide,” “halogen” or “halo” as used herein alone or as partof another group refer to chlorine, bromine, fluorine, and iodine.

The term “heteroatom” shall mean atoms other than carbon and hydrogen.

The terms “hydrocarbon” and “hydrocarbyl” as used herein describeorganic compounds or radicals consisting exclusively of the elementscarbon and hydrogen. These moieties include alkyl, alkenyl, alkynyl, andaryl moieties. These moieties also include alkyl, alkenyl, alkynyl, andaryl moieties substituted with other aliphatic or cyclic hydrocarbongroups, such as alkaryl, alkenaryl and alkynaryl. Unless otherwiseindicated, these moieties preferably comprise 1 to 20 carbon atoms.

The term “rock salt” as used herein describes a cubic structure in whichmetal cations (“M”) occupy all of the octahedral sites of the cubicstructure, resulting in the stoichiometry MO. Furthermore, the metalsare indistinguishable from one another regardless of whether the metalsare the same element or a random distribution of different elements.

The term “silyl” as used herein describes substituents of the generalformula —Si(X⁸)(X⁹)(X¹⁰) where X⁸, X⁹, and X¹⁰ are independentlyhydrocarbyl or substituted hydrocarbyl.

The “substituted hydrocarbyl” moieties described herein are hydrocarbylmoieties which are substituted with at least one atom other than carbon,including moieties in which a carbon chain atom is substituted with ahetero atom such as nitrogen, oxygen, silicon, phosphorous, boron,sulfur, or a halogen atom. These substituents include halogen,heterocyclo, alkoxy, alkenoxy, alkynoxy, aryloxy, hydroxy, protectedhydroxy, keto, acyl, acyloxy, nitro, amino, amido, nitro, cyano, thiol,ketals, acetals, esters, ethers, and thioethers.

The term “transmissivity” refers to the fraction of light transmittedthrough an electrochromic film. Unless otherwise stated, thetransmissivity of an electrochromic film is represented by the numberTvis. Tvis is calculated/obtained by integrating the transmissionspectrum in the wavelength range of 400-730 nm using the spectralphotopic efficiency I_p(lambda) (CIE, 1924) as a weighting factor. (Ref:ASTM E1423).

The term “transparent” is used to denote substantial transmission ofelectromagnetic radiation through a material such that, for example,bodies situated beyond or behind the material can be distinctly seen orimaged using appropriate image sensing technology.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In accordance with one aspect of the present invention, anodicelectrochromic layers comprising lithium nickel oxides and molybdenum,tungsten or a combination thereof having a range of desirable propertiesand characteristics may be prepared. For example, in one embodiment theanodic electrochromic material may have a bleached state voltage valuesignificantly greater than 2.0V. In another embodiment, the anodicelectrochromic material is provided in an electrochemically andoptically matched (EOM) state relative to a cathodic electrochromicmaterial in its fully bleached state for use in an electrochromicdevice. In another embodiment, the anodic electrochromic material isrelatively stable; for example, the lithium nickel oxide material doesnot darken from its fully bleached state or deactivate (e.g., remaintransparent but no longer function as an electrochromic anode materialor film) at elevated temperatures in the presence of ambient air.

Advantageously, molybdenum and tungsten promote the formation ofelectrochromic lithium nickel oxide materials having favorable bleachedstate characteristics. In another embodiment, the electrochromic nickeloxide material comprises molybdenum. In another embodiment, theelectrochromic nickel oxide material comprises tungsten. In anotherembodiment, the electrochromic nickel oxide material comprisesmolybdenum and tungsten. In another embodiment, the electrochromicnickel oxide material comprises molybdenum but not tungsten. In anotherembodiment, electrochromic nickel oxide material comprises tungsten butnot molybdenum.

In certain embodiments, the anodic electrochromic material ischaracterized by a largest d-spacing of at least 2.5 Å by diffractiontechniques such as electron diffraction (“ED”) and X-ray diffraction(“XRD”) analysis. For example, in one embodiment the lithium nickeloxide material is characterized by a largest d-spacing of at least 2.75Å. By way of further example, in one embodiment the anodicelectrochromic material is characterized by a largest d-spacing of atleast 3 Å. By way of further example, in one embodiment the anodicelectrochromic material is characterized by a largest d-spacing of atleast 3 Å. By way of further example, in one embodiment the anodicelectrochromic material is characterized by a largest d-spacing of atleast 3.5 Å. By way of further example, in one embodiment the anodicelectrochromic material is characterized by a largest d-spacing of atleast 4 Å. By way of further example, in one embodiment the anodicelectrochromic material is characterized by a largest d-spacing of atleast 4.5 Å. By way of further example, in one embodiment the anodicelectrochromic material exhibits long range ordering as measured by thepresence of at least one reflection peak in the XRD pattern between 0and 80 degrees (2θ) when measured with copper Kα radiation. By way offurther example, in one embodiment the I anodic electrochromic materialexhibits long range ordering as measured by the presence of at least onereflection peak in the XRD pattern below 26 degrees (2θ) when measuredwith copper Kα radiation. In each of the foregoing examples, the anodicelectrochromic composition may comprise molybdenum, tungsten or acombination thereof. In one such embodiment, the anodic electrochromiccomposition comprises molybdenum. In another such embodiment, thelithium nickel oxide composition comprises tungsten.

In certain embodiments, the anodic electrochromic material ischaracterized by a coloration efficiency absolute (non-negative) valueof at least 19 cm²/C (alternatively expressed as negative value −19cm²/C, −20 cm²/C, −21 cm²/C, and so on). By way of further example, theanodic electrochromic material has a coloration efficiency in the rangeof about −19 cm²/C to about −60 cm²/C. By way of further example, theanodic electrochromic layer has a coloration efficiency in the range ofabout −24 cm²/C to about −32 cm²/C.

In accordance with one aspect of the present invention, the relativeamounts of lithium, nickel, and tungsten in the anodic electrochromicmaterial are controlled such that an atomic ratio of the amount oflithium to the combined amount of nickel and tungsten (i.e., Li:[Ni+W])in the electrochromic layer is generally at least about 0.4:1. By way offurther example, in one such embodiment the atomic ratio of lithium tothe combined amount of nickel and tungsten in the electrochromic layermaterial is at least about 0.75:1, respectively. By way of furtherexample, in one such embodiment the atomic ratio of lithium to thecombined amount of nickel and tungsten in the electrochromic layer is atleast about 0.9:1, respectively. By way of further example, in one suchembodiment the atomic ratio of lithium to the combined amount of nickeland tungsten in the electrochromic layer material is at least about 1:1,respectively. By way of further example, in one such embodiment theatomic ratio of lithium to the combined amount of nickel and tungsten inthe electrochromic lithium nickel oxide material is at least about1.25:1, respectively. By way of further example, in one such embodimentthe atomic ratio of lithium to the combined amount of nickel andtungsten in the electrochromic material is at least about 1.5:1,respectively. By way of further example, in one such embodiment theatomic ratio of lithium to the combined amount of nickel and tungsten inthe electrochromic material is at least about 2:1, respectively. By wayof further example, in one such embodiment the atomic ratio of lithiumto the combined amount of nickel and tungsten in the electrochromicmaterial is at least about 2.5:1, respectively. In certain embodiments,the atomic ratio of lithium to the combined amount of nickel andtungsten in the electrochromic material will not exceed about 4:1,respectively. In some embodiments, therefore, the atomic ratio oflithium to the combined amount of nickel and tungsten in theelectrochromic material will be in the range about 0.75:1 to about 3:1,respectively. In some embodiments, therefore, the atomic ratio oflithium to the combined amount of nickel and tungsten in theelectrochromic lithium nickel oxide material will be in the range about0.9:1 to about 2.5:1, respectively. In some embodiments, therefore, theatomic ratio of lithium to the combined amount of nickel and tungsten inthe electrochromic lithium nickel oxide material will be in the rangeabout 1:1 to about 2.5:1, respectively. In some embodiments, therefore,the atomic ratio of lithium to the combined amount of nickel andtungsten in the electrochromic lithium nickel oxide material will be inthe range about 1.1:1 to about 1.5:1, respectively. In some embodiments,therefore, the atomic ratio of lithium to the combined amount of nickeland tungsten in the electrochromic lithium nickel oxide material will bein the range about 1.5:1 to about 2:1, respectively. In someembodiments, therefore, the atomic ratio of lithium to the combinedamount of nickel and tungsten in the electrochromic lithium nickel oxidematerial will be in the range about 2:1 to about 2.5:1, respectively.

In one embodiment, the relative amounts of lithium, nickel, and tungstenin the anodic electrochromic layer are controlled such that an atomicratio of the amount of lithium to the combined amount of nickel andtungsten (i.e., Li:[Ni+W]) in the anodic electrochromic layer isgenerally less than 1.75:1, respectively, when the anodic electrochromiclayer is in its fully bleached state. For example, in one suchembodiment the atomic ratio of lithium to the combined amount of nickeland tungsten in the anodic electrochromic layer is less than 1.5:1,respectively, when the anodic electrochromic layer is in its fullybleached state. By way of further example, in one such embodiment theatomic ratio of lithium to the combined amount of nickel and tungsten inthe electrochromic lithium nickel oxide material is less than 1.45:1,respectively, when the electrochromic lithium nickel oxide material isin its fully bleached state. By way of further example, in one suchembodiment the atomic ratio of lithium to the combined amount of nickeland tungsten in the electrochromic lithium nickel oxide material is lessthan 1.4:1, respectively, when the electrochromic lithium nickel oxidematerial is in its fully bleached state. By way of further example, inone such embodiment the atomic ratio of lithium to the combined amountof nickel and tungsten in the electrochromic lithium nickel oxidematerial is less than 1.35:1, respectively, when the electrochromiclithium nickel oxide material is in its fully bleached state. By way offurther example, in one such embodiment the atomic ratio of lithium tothe combined amount of nickel and tungsten in the electrochromic lithiumnickel oxide material is less than 1.3:1, respectively, when theelectrochromic lithium nickel oxide material is in its fully bleachedstate. By way of further example, in one such embodiment the atomicratio of lithium to the combined amount of nickel and tungsten in theelectrochromic lithium nickel oxide material is less than 1.25:1,respectively, when the electrochromic lithium nickel oxide material isin its fully bleached state. By way of further example, in one suchembodiment the atomic ratio of lithium to the combined amount of nickeland tungsten in the electrochromic lithium nickel oxide material is lessthan 1.2:1, respectively, when the electrochromic lithium nickel oxidematerial is in its fully bleached state. By way of further example, inone such embodiment the atomic ratio of lithium to the combined amountof nickel and tungsten in the electrochromic lithium nickel oxidematerial is less than 1.15:1, respectively, when the electrochromiclithium nickel oxide material is in its fully bleached state. By way offurther example, in one such embodiment the atomic ratio of lithium tothe combined amount of nickel and tungsten in the electrochromic lithiumnickel oxide material is less than 1.1:1, respectively, when theelectrochromic lithium nickel oxide material is in its fully bleachedstate. By way of further example, in one such embodiment the atomicratio of lithium to the combined amount of nickel and tungsten in theelectrochromic lithium nickel oxide material is less than 1.05:1,respectively, when the electrochromic lithium nickel oxide material isin its fully bleached state. By way of further example, in one suchembodiment the atomic ratio of lithium to the combined amount of nickeland tungsten in the electrochromic lithium nickel oxide material is lessthan 1:1, respectively, when the electrochromic lithium nickel oxidematerial is in its fully bleached state. By way of further example, inone such embodiment the atomic ratio of lithium to the combined amountof nickel and tungsten in the electrochromic lithium nickel oxidematerial is in the range of about 0.4:1 to 1.5:1, respectively, when theelectrochromic lithium nickel oxide material is in its fully bleachedstate. By way of further example, in one such embodiment the atomicratio of lithium to the combined amount of nickel and tungsten in theelectrochromic lithium nickel oxide material is in the range of about0.5:1 to 1.4:1, respectively, when the electrochromic lithium nickeloxide material is in its fully bleached state. In certain embodiments,the atomic ratio of lithium to the combined amount of nickel andtungsten in the electrochromic lithium nickel oxide material is in therange of about 0.6:1 to 1.35:1, respectively, when the electrochromiclithium nickel oxide material is in its fully bleached state. In certainembodiments, the atomic ratio of lithium to the combined amount ofnickel and tungsten in the electrochromic lithium nickel oxide materialis in the range of about 0.7:1 to 1.35:1, respectively, when theelectrochromic lithium nickel oxide material is in its fully bleachedstate. In certain embodiments, the atomic ratio of lithium to thecombined amount of nickel and tungsten in the electrochromic lithiumnickel oxide material is in the range of about 0.8:1 to 1.35:1,respectively, when the electrochromic lithium nickel oxide material isin its fully bleached state. In certain embodiments, the atomic ratio oflithium to the combined amount of nickel and tungsten in theelectrochromic lithium nickel oxide material is in the range of about0.9:1 to 1.35:1, respectively, when the electrochromic lithium nickeloxide material is in its fully bleached state.

In accordance with one aspect of the present invention, the relativeamounts of lithium, nickel and molybdenum in the anodic electrochromiclayer are controlled such that an atomic ratio of the amount of lithiumto the combined amount of nickel and molybdenum (i.e., Li:[Ni+Mo]) inthe anodic electrochromic layer is generally at least about 0.4:1. Byway of further example, in one such embodiment the atomic ratio oflithium to the combined amount of nickel and molybdenum in theelectrochromic lithium nickel oxide material is at least about 0.75:1,respectively. By way of further example, in one such embodiment theatomic ratio of lithium to the combined amount of nickel and molybdenumin the electrochromic lithium nickel oxide material is at least about0.9:1, respectively. By way of further example, in one such embodimentthe atomic ratio of lithium to the combined amount of nickel andmolybdenum in the electrochromic lithium nickel oxide material is atleast about 1:1, respectively. By way of further example, in one suchembodiment the atomic ratio of lithium to the combined amount of nickeland molybdenum in the electrochromic lithium nickel oxide material is atleast about 1.25:1, respectively. By way of further example, in one suchembodiment the atomic ratio of lithium to the combined amount of nickeland molybdenum in the electrochromic lithium nickel oxide material is atleast about 1.5:1, respectively. By way of further example, in one suchembodiment the atomic ratio of lithium to the combined amount of nickeland molybdenum in the electrochromic lithium nickel oxide material is atleast about 2:1, respectively. By way of further example, in one suchembodiment the atomic ratio of lithium to the combined amount of nickeland molybdenum in the electrochromic lithium nickel oxide material is atleast about 2.5:1, respectively. In certain embodiments, the atomicratio of lithium to the combined amount of nickel and molybdenum in theelectrochromic lithium nickel oxide material will not exceed about 4:1,respectively. In some embodiments, therefore, the atomic ratio oflithium to the combined amount of nickel and molybdenum in theelectrochromic lithium nickel oxide material will be in the range about0.75:1 to about 3:1, respectively. In some embodiments, therefore, theatomic ratio of lithium to the combined amount of nickel and molybdenumin the electrochromic lithium nickel oxide material will be in the rangeabout 0.9:1 to about 2.5:1, respectively. In some embodiments,therefore, the atomic ratio of lithium to the combined amount of nickeland molybdenum in the electrochromic lithium nickel oxide material willbe in the range about 1:1 to about 2.5:1, respectively. In someembodiments, therefore, the atomic ratio of lithium to the combinedamount of nickel and molybdenum in the electrochromic lithium nickeloxide material will be in the range about 1.1:1 to about 1.5:1,respectively. In some embodiments, therefore, the atomic ratio oflithium to the combined amount of nickel and molybdenum in theelectrochromic lithium nickel oxide material will be in the range about1.5:1 to about 2:1, respectively. In some embodiments, therefore, theatomic ratio of lithium to the combined amount of nickel and molybdenumin the electrochromic lithium nickel oxide material will be in the rangeabout 2:1 to about 2.5:1, respectively.

In one embodiment, the relative amounts of lithium, nickel, andmolybdenum in the anodic electrochromic layer are controlled such thatan atomic ratio of the amount of lithium to the combined amount ofnickel and molybdenum (i.e., Li:[Ni+Mo]) in the anodic electrochromiclayer is generally less than 1.75:1, respectively, when the anodicelectrochromic layer is in its fully bleached state. For example, in onesuch embodiment the atomic ratio of lithium to the combined amount ofnickel and molybdenum in the electrochromic lithium nickel oxidematerial is less than 1.5:1, respectively, when the electrochromiclithium nickel oxide material is in its fully bleached state. By way offurther example, in one such embodiment the atomic ratio of lithium tothe combined amount of nickel and molybdenum in the electrochromiclithium nickel oxide material is less than 1.45:1, respectively, whenthe electrochromic lithium nickel oxide material is in its fullybleached state. By way of further example, in one such embodiment theatomic ratio of lithium to the combined amount of nickel and molybdenumin the electrochromic lithium nickel oxide material is less than 1.4:1,respectively, when the electrochromic lithium nickel oxide material isin its fully bleached state. By way of further example, in one suchembodiment the atomic ratio of lithium to the combined amount of nickeland molybdenum in the electrochromic lithium nickel oxide material isless than 1.35:1, respectively, when the electrochromic lithium nickeloxide material is in its fully bleached state. By way of furtherexample, in one such embodiment the atomic ratio of lithium to thecombined amount of nickel and molybdenum in the electrochromic lithiumnickel oxide material is less than 1.3:1, respectively, when theelectrochromic lithium nickel oxide material is in its fully bleachedstate. By way of further example, in one such embodiment the atomicratio of lithium to the combined amount of nickel and molybdenum in theelectrochromic lithium nickel oxide material is less than 1.25:1,respectively, when the electrochromic lithium nickel oxide material isin its fully bleached state. By way of further example, in one suchembodiment the atomic ratio of lithium to the combined amount of nickeland molybdenum in the electrochromic lithium nickel oxide material isless than 1.2:1, respectively, when the electrochromic lithium nickeloxide material is in its fully bleached state. By way of furtherexample, in one such embodiment the atomic ratio of lithium to thecombined amount of nickel and molybdenum in the electrochromic lithiumnickel oxide material is less than 1.15:1, respectively, when theelectrochromic lithium nickel oxide material is in its fully bleachedstate. By way of further example, in one such embodiment the atomicratio of lithium to the combined amount of nickel and molybdenum in theelectrochromic lithium nickel oxide material is less than 1.1:1,respectively, when the electrochromic lithium nickel oxide material isin its fully bleached state. By way of further example, in one suchembodiment the atomic ratio of lithium to the combined amount of nickeland molybdenum in the electrochromic lithium nickel oxide material isless than 1.05:1, respectively, when the electrochromic lithium nickeloxide material is in its fully bleached state. By way of furtherexample, in one such embodiment the atomic ratio of lithium to thecombined amount of nickel and molybdenum in the electrochromic lithiumnickel oxide material is less than 1:1, respectively, when theelectrochromic lithium nickel oxide material is in its fully bleachedstate. By way of further example, in one such embodiment the atomicratio of lithium to the combined amount of nickel and molybdenum in theelectrochromic lithium nickel oxide material is in the range of about0.4:1 to 1.5:1, respectively, when the electrochromic lithium nickeloxide material is in its fully bleached state. By way of furtherexample, in one such embodiment the atomic ratio of lithium to thecombined amount of nickel and molybdenum in the electrochromic lithiumnickel oxide material is in the range of about 0.5:1 to 1.4:1,respectively, when the electrochromic lithium nickel oxide material isin its fully bleached state. In certain embodiments, the atomic ratio oflithium to the combined amount of nickel and molybdenum in theelectrochromic lithium nickel oxide material is in the range of about0.6:1 to 1.35:1, respectively, when the electrochromic lithium nickeloxide material is in its fully bleached state. In certain embodiments,the atomic ratio of lithium to the combined amount of nickel andmolybdenum in the electrochromic lithium nickel oxide material is in therange of about 0.7:1 to 1.35:1, respectively, when the electrochromiclithium nickel oxide material is in its fully bleached state. In certainembodiments, the atomic ratio of lithium to the combined amount ofnickel and molybdenum in the electrochromic lithium nickel oxidematerial is in the range of about 0.8:1 to 1.35:1, respectively, whenthe electrochromic lithium nickel oxide material is in its fullybleached state. In certain embodiments, the atomic ratio of lithium tothe combined amount of nickel and molybdenum in the electrochromiclithium nickel oxide material is in the range of about 0.9:1 to 1.35:1,respectively, when the electrochromic lithium nickel oxide material isin its fully bleached state.

In accordance with one aspect of the present invention, the relativeamounts of lithium, nickel, molybdenum and tungsten in the anodicelectrochromic layer are controlled such that an atomic ratio of theamount of lithium to the combined amount of nickel, molybdenum andtungsten (i.e., Li:[Ni+Mo+W]) in the anodic electrochromic layer isgenerally at least about 0.4:1. By way of further example, in one suchembodiment the atomic ratio of lithium to the combined amount of nickel,molybdenum and tungsten in the electrochromic lithium nickel oxidematerial is at least about 0.75:1, respectively. By way of furtherexample, in one such embodiment the atomic ratio of lithium to thecombined amount of nickel, molybdenum and tungsten in the electrochromiclithium nickel oxide material is at least about 0.9:1, respectively. Byway of further example, in one such embodiment the atomic ratio oflithium to the combined amount of nickel, molybdenum and tungsten in theelectrochromic lithium nickel oxide material is at least about 1:1,respectively. By way of further example, in one such embodiment theatomic ratio of lithium to the combined amount of nickel, molybdenum andtungsten in the electrochromic lithium nickel oxide material is at leastabout 1.25:1, respectively. By way of further example, in one suchembodiment the atomic ratio of lithium to the combined amount of nickel,molybdenum and tungsten in the electrochromic lithium nickel oxidematerial is at least about 1.5:1, respectively. By way of furtherexample, in one such embodiment the atomic ratio of lithium to thecombined amount of nickel, molybdenum and tungsten in the electrochromiclithium nickel oxide material is at least about 2:1, respectively. Byway of further example, in one such embodiment the atomic ratio oflithium to the combined amount of nickel, molybdenum and tungsten in theelectrochromic lithium nickel oxide material is at least about 2.5:1,respectively. In certain embodiments, the atomic ratio of lithium to thecombined amount of nickel, molybdenum and tungsten in the electrochromiclithium nickel oxide material will not exceed about 4:1, respectively.In some embodiments, therefore, the atomic ratio of lithium to thecombined amount of nickel, molybdenum and tungsten in the electrochromiclithium nickel oxide material will be in the range about 0.75:1 to about3:1, respectively. In some embodiments, therefore, the atomic ratio oflithium to the combined amount of nickel, molybdenum and tungsten in theelectrochromic lithium nickel oxide material will be in the range about0.9:1 to about 2.5:1, respectively. In some embodiments, therefore, theatomic ratio of lithium to the combined amount of nickel, molybdenum andtungsten in the electrochromic lithium nickel oxide material will be inthe range about 1:1 to about 2.5:1, respectively. In some embodiments,therefore, the atomic ratio of lithium to the combined amount of nickel,molybdenum and tungsten in the electrochromic lithium nickel oxidematerial will be in the range about 1.1:1 to about 1.5:1, respectively.In some embodiments, therefore, the atomic ratio of lithium to thecombined amount of nickel, molybdenum and tungsten in the electrochromiclithium nickel oxide material will be in the range about 1.5:1 to about2:1, respectively. In some embodiments, therefore, the atomic ratio oflithium to the combined amount of nickel, molybdenum and tungsten in theanodic electrochromic layer will be in the range about 2:1 to about2.5:1, respectively.

In one embodiment, the relative amounts of lithium, nickel, molybdenum,and tungsten in the anodic electrochromic layer are controlled such thatan atomic ratio of the amount of lithium to the combined amount ofnickel molybdenum, and tungsten (i.e., Li:[Ni+Mo+W]) in the anodicelectrochromic layer is generally less than 1.75:1, respectively, whenthe anodic electrochromic layer is in its fully bleached state. Forexample, in one such embodiment the atomic ratio of lithium to thecombined amount of nickel, molybdenum and tungsten in the electrochromiclithium nickel oxide material is less than 1.5:1, respectively, when theelectrochromic lithium nickel oxide material is in its fully bleachedstate. By way of further example, in one such embodiment the atomicratio of lithium to the combined amount of nickel, molybdenum andtungsten in the electrochromic lithium nickel oxide material is lessthan 1.45:1, respectively, when the electrochromic lithium nickel oxidematerial is in its fully bleached state. By way of further example, inone such embodiment the atomic ratio of lithium to the combined amountof nickel, molybdenum and tungsten in the electrochromic lithium nickeloxide material is less than 1.4:1, respectively, when the electrochromiclithium nickel oxide material is in its fully bleached state. By way offurther example, in one such embodiment the atomic ratio of lithium tothe combined amount of nickel, molybdenum and tungsten in theelectrochromic lithium nickel oxide material is less than 1.35:1,respectively, when the electrochromic lithium nickel oxide material isin its fully bleached state. By way of further example, in one suchembodiment the atomic ratio of lithium to the combined amount of nickel,molybdenum and tungsten in the electrochromic lithium nickel oxidematerial is less than 1.3:1, respectively, when the electrochromiclithium nickel oxide material is in its fully bleached state. By way offurther example, in one such embodiment the atomic ratio of lithium tothe combined amount of nickel, molybdenum and tungsten in theelectrochromic lithium nickel oxide material is less than 1.25:1,respectively, when the electrochromic lithium nickel oxide material isin its fully bleached state. By way of further example, in one suchembodiment the atomic ratio of lithium to the combined amount of nickel,molybdenum and tungsten in the electrochromic lithium nickel oxidematerial is less than 1.2:1, respectively, when the electrochromiclithium nickel oxide material is in its fully bleached state. By way offurther example, in one such embodiment the atomic ratio of lithium tothe combined amount of nickel, molybdenum and tungsten in theelectrochromic lithium nickel oxide material is less than 1.15:1,respectively, when the electrochromic lithium nickel oxide material isin its fully bleached state. By way of further example, in one suchembodiment the atomic ratio of lithium to the combined amount of nickel,molybdenum and tungsten in the electrochromic lithium nickel oxidematerial is less than 1.1:1, respectively, when the electrochromiclithium nickel oxide material is in its fully bleached state. By way offurther example, in one such embodiment the atomic ratio of lithium tothe combined amount of nickel, molybdenum and tungsten in theelectrochromic lithium nickel oxide material is less than 1.05:1,respectively, when the electrochromic lithium nickel oxide material isin its fully bleached state. By way of further example, in one suchembodiment the atomic ratio of lithium to the combined amount of nickel,molybdenum and tungsten in the electrochromic lithium nickel oxidematerial is less than 1:1, respectively, when the electrochromic lithiumnickel oxide material is in its fully bleached state. By way of furtherexample, in one such embodiment the atomic ratio of lithium to thecombined amount of nickel, molybdenum and tungsten in the electrochromiclithium nickel oxide material is in the range of about 0.4:1 to 1.5:1,respectively, when the electrochromic lithium nickel oxide material isin its fully bleached state. By way of further example, in one suchembodiment the atomic ratio of lithium to the combined amount of nickel,molybdenum and tungsten in the electrochromic lithium nickel oxidematerial is in the range of about 0.5:1 to 1.4:1, respectively, when theelectrochromic lithium nickel oxide material is in its fully bleachedstate. In certain embodiments, the atomic ratio of lithium to thecombined amount of nickel, molybdenum and tungsten in the electrochromiclithium nickel oxide material is in the range of about 0.6:1 to 1.35:1,respectively, when the electrochromic lithium nickel oxide material isin its fully bleached state. In certain embodiments, the atomic ratio oflithium to the combined amount of nickel, molybdenum and tungsten in theelectrochromic lithium nickel oxide material is in the range of about0.7:1 to 1.35:1, respectively, when the electrochromic lithium nickeloxide material is in its fully bleached state. In certain embodiments,the atomic ratio of lithium to the combined amount of nickel, molybdenumand tungsten in the electrochromic lithium nickel oxide material is inthe range of about 0.8:1 to 1.35:1, respectively, when theelectrochromic lithium nickel oxide material is in its fully bleachedstate. In certain embodiments, the atomic ratio of lithium to thecombined amount of nickel, molybdenum and tungsten in the electrochromiclithium nickel oxide material is in the range of about 0.9:1 to 1.35:1,respectively, when the electrochromic lithium nickel oxide material isin its fully bleached state.

In general, increasing the amount of molybdenum and/or tungsten relativeto the amount of nickel in the anodic electrochromic layer increases thestability of the bleached state and the bleached state voltage of thematerial but it also tends to decrease its volumetric charge capacity.Anodic electrochromic layers having large amounts of molybdenum and/ortungsten relative to nickel, such as those in which the atomic ratio ofthe combined amount of molybdenum and tungsten to the combined amount ofnickel, molybdenum and tungsten (i.e., [Mo+W]:[Ni+Mo+W]) is greater thanabout 0.8:1, respectively, tend to have stable fully bleached states,but sub-optimal charge capacities and darkened state transmissivities.Thus, in certain embodiments it is preferred that the atomic ratio ofthe combined amount of molybdenum and tungsten to the combined amount ofnickel, molybdenum and tungsten in the anodic electrochromic layer beless than about 0.8:1 (i.e., [Mo+W]:[Ni+Mo+W]). For example, in one suchembodiment the atomic ratio of the combined amount of molybdenum andtungsten to the combined amount of nickel, molybdenum and tungsten inthe electrochromic lithium nickel oxide material is less than about0.7:1 (i.e., [Mo+W]:[Ni+Mo+W]). By way of further example, in one suchembodiment the atomic ratio of the combined amount of molybdenum andtungsten to the combined amount of nickel, molybdenum and tungsten inthe electrochromic lithium nickel oxide material is less than about0.6:1. By way of further example, in one such embodiment the atomicratio of the combined amount of molybdenum and tungsten to the combinedamount of nickel, molybdenum and tungsten in the electrochromic lithiumnickel oxide material is less than about 0.5:1. By way of furtherexample, in one such embodiment the atomic ratio of the combined amountof molybdenum and tungsten to the combined amount of nickel, molybdenumand tungsten in the anodic electrochromic layer is less than about0.4:1.

Conversely, anodic electrochromic layers having small amounts ofmolybdenum and/or tungsten relative to nickel, such as those in whichthe atomic ratio of the combined amount of molybdenum and tungsten tothe combined amount of nickel, molybdenum and tungsten (i.e.,[Mo+W]:[Ni+Mo+W])) is less than about 0.025:1, respectively, tend tohave relatively high charge capacities but less stable fully bleachedstates. Thus, in certain embodiments it is preferred that the ratio(atomic) of the combined amount of molybdenum and tungsten to thecombined amount of nickel, molybdenum and tungsten in the anodicelectrochromic layer be greater than about 0.03:1 (i.e.,[Mo+W]:[Ni+Mo+W]). For example, in one such embodiment the atomic ratioof the combined amount of molybdenum and tungsten to the combined amountof nickel, molybdenum and tungsten in the electrochromic lithium nickeloxide material is greater than about 0.04:1 (i.e., [Mo+W]:[Ni+Mo+W]). Byway of further example, in one such embodiment the atomic ratio of thecombined amount of molybdenum and tungsten to the combined amount ofnickel, molybdenum and tungsten in the electrochromic lithium nickeloxide material is greater than about 0.05:1. By way of further example,in one such embodiment the atomic ratio of the combined amount ofmolybdenum and tungsten to the combined amount of nickel, molybdenum andtungsten in the electrochromic lithium nickel oxide material is greaterthan about 0.075:1. By way of further example, in one such embodimentthe atomic ratio of the combined amount of molybdenum and tungsten tothe combined amount of nickel, molybdenum and tungsten in the anodicelectrochromic layer is greater than about 0.1:1. In each of theforegoing examples and embodiments recited in this paragraph, thelithium nickel oxide composition may comprise molybdenum but nottungsten, tungsten but not molybdenum, or molybdenum and tungsten.

In certain embodiments, the ratio (atomic) of molybdenum to the combinedamount nickel and molybdenum in the anodic electrochromic layer will bein the range of about 0.025:1 to about 0.8:1 (Mo:[Ni+Mo]). For example,in one such embodiment the atomic ratio of molybdenum to the combinedamount nickel and molybdenum in the anodic electrochromic layer will bein the range of about 0.05:1 and about 0.7:1 (Mo:[Ni+Mo]). By way offurther example, in one such embodiment the atomic ratio of molybdenumto the combined amount nickel and molybdenum in the anodicelectrochromic lithium nickel oxide material will be in the range ofabout 0.075:1 and about 0.6:1 (Mo:[Ni+Mo]). By way of further example,in one such embodiment the atomic ratio of molybdenum to the combinedamount nickel and molybdenum in the anodic electrochromic lithium nickeloxide material will be in the range of about 0.1:1 and about 0.55:1(Mo:[Ni+Mo]). By way of further example, in one such embodiment theatomic ratio of molybdenum to the combined amount nickel and molybdenumin the anodic electrochromic lithium nickel oxide material will be inthe range of about 0.15:1 and about 0.5:1 (Mo:[Ni+Mo]). By way offurther example, in one such embodiment the atomic ratio of molybdenumto the combined amount nickel and molybdenum in the anodicelectrochromic lithium nickel oxide material will be in the range ofabout 0.175:1 and about 0.45:1 (Mo:[Ni+Mo]). By way of further example,in one such embodiment the atomic ratio of molybdenum to the combinedamount nickel and molybdenum in the anodic electrochromic layer will bein the range of about 0.2:1 and about 0.4:1 (Mo:[Ni+Mo]).

In certain embodiments, the ratio (atomic) of tungsten to the combinedamount nickel and tungsten in the anodic electrochromic layer will be inthe range of about 0.025:1 to about 0.8:1 (W:[Ni+W]). For example, inone such embodiment the atomic ratio of tungsten to the combined amountnickel and tungsten in the anodic electrochromic lithium nickel oxidematerial will be in the range of about 0.05:1 and about 0.7:1(W:[Ni+W]). By way of further example, in one such embodiment the atomicratio of tungsten to the combined amount nickel and tungsten in theanodic electrochromic lithium nickel oxide material will be in the rangeof about 0.075:1 and about 0.6:1 (W:[Ni+W]). By way of further example,in one such embodiment the atomic ratio of tungsten to the combinedamount nickel and tungsten in the anodic electrochromic lithium nickeloxide material will be in the range of about 0.1:1 and about 0.55:1(W:[Ni+W]). By way of further example, in one such embodiment the atomicratio of tungsten to the combined amount nickel and tungsten in theanodic electrochromic lithium nickel oxide material will be in the rangeof about 0.15:1 and about 0.5:1 (W:[Ni+W]). By way of further example,in one such embodiment the atomic ratio of tungsten to the combinedamount nickel and tungsten in the anodic electrochromic lithium nickeloxide material will be in the range of about 0.175:1 and about 0.45:1(W:[Ni+W]). By way of further example, in one such embodiment the atomicratio of tungsten to the combined amount nickel and tungsten in theanodic electrochromic layer will be in the range of about 0.2:1 andabout 0.4:1 (W:[Ni+W]).

In general, the ratio (atomic) of the combined amount of molybdenum andtungsten to the combined amount nickel, molybdenum and tungsten in theanodic electrochromic layer will typically be in the range of about0.025:1 to about 0.8:1 ([Mo+W]:[Ni+Mo+W]). For example, in one suchembodiment the atomic ratio of the combined amount of molybdenum andtungsten to the combined amount nickel, molybdenum and tungsten in theanodic electrochromic lithium nickel oxide material will typically be inthe range of about 0.05:1 and about 0.7:1 ([Mo+W]:[Ni+Mo+W]). By way offurther example, in one such embodiment the atomic ratio of the combinedamount of molybdenum and tungsten to the combined amount nickel,molybdenum and tungsten in the anodic electrochromic lithium nickeloxide material will typically be in the range of about 0.075:1 and about0.6:1 ([Mo+W]:[Ni+Mo+W]). By way of further example, in one suchembodiment the atomic ratio of the combined amount of molybdenum andtungsten to the combined amount nickel, molybdenum and tungsten in theanodic electrochromic lithium nickel oxide material will be in the rangeof about 0.1:1 and about 0.55:1 ([Mo+W]:[Ni+Mo+W]). By way of furtherexample, in one such embodiment the atomic ratio of the combined amountof molybdenum and tungsten to the combined amount nickel, molybdenum andtungsten in the anodic electrochromic lithium nickel oxide material willbe in the range of about 0.15:1 and about 0.5:1 (W:[Ni+Mo+W]). By way offurther example, in one such embodiment the atomic ratio of the combinedamount of molybdenum and tungsten to the combined amount nickel,molybdenum and tungsten in the anodic electrochromic lithium nickeloxide material will be in the range of about 0.175:1 and about 0.45:1([Mo+W]:[Ni+Mo+W]). By way of further example, in one such embodimentthe atomic ratio of the combined amount of molybdenum and tungsten tothe combined amount nickel, molybdenum and tungsten in the anodicelectrochromic layer will be in the range of about 0.2:1 and about 0.4:1([Mo+W]:[Ni+Mo+W]).

In one embodiment, the electrochromic material comprises one or morebleached state stabilizing elements selected from the group consistingof Group 3, Group 4, Group 6, Group 13, Group 14 and Group 15 elements(IUPAC classification), and combinations thereof in addition tomolybdenum and tungsten. In such embodiments, the relative amounts oflithium, nickel, molybdenum, tungsten and the bleached state stabilizingelement(s) in the anodic electrochromic layer are controlled such thatan atomic ratio of the amount of lithium to the combined amount ofnickel, molybdenum, tungsten and bleached state stabilizing element(s)in the anodic electrochromic layer is generally at least about 0.4:1,respectively, wherein the bleached state stabilizing element(s) is/areselected from the group consisting of Group 3, Group 4, Group 5, Group13, Group 14 and Group 15 elements, and combinations thereof. Forexample, in one embodiment, the atomic ratio of lithium to the combinedamount of nickel and all Group 6 metal(s) and bleached state stabilizingelements, i.e., Li:[Ni+Mo+W+M], in the electrochromic lithium nickeloxide material is at least about 0.4:1, respectively, wherein M is ableached state stabilizing element selected from the group consisting ofY, Ti, Zr, Hf, V, Nb, Ta, B, Al, Ga, In, Si, Ge, Sn, P, Sb, andcombinations thereof; stated differently, the ratio of the amount oflithium to the combined amount of Ni, Y, Ti, Zr, Hf, V, Nb, Ta, Mo, W,B, Al, Ga, In, Si, Ge, Sn, P, and Sb, in the electrochromic lithiumnickel oxide material is at least 0.4:1 (atomic ratio), respectively. Byway of further example, in one such embodiment the atomic ratio oflithium to the combined amount of Ni, Y, Ti, Zr, Hf, V, Nb, Ta, Mo, W,B, Al, Ga, In, Si, Ge, Sn, P, and Sb is at least about 0.75:1,respectively. By way of further example, in one such embodiment theatomic ratio of lithium to the combined amount of Ni, Y, Ti, Zr, Hf, V,Nb, Ta, Mo, W, B, Al, Ga, In, Si, Ge, Sn, P, and Sb is at least about0.9:1, respectively. By way of further example, in one such embodimentthe atomic ratio of lithium to the combined amount of Ni, Y, Ti, Zr, Hf,V, Nb, Ta, Mo, W, B, Al, Ga, In, Si, Ge, Sn, P, and Sb is at least about1:1, respectively. By way of further example, in one such embodiment theatomic ratio of lithium to the combined amount of Ni, Y, Ti, Zr, Hf, V,Nb, Ta, Mo, W, B, Al, Ga, In, Si, Ge, Sn, P, and Sb is at least about1.25:1, respectively. By way of further example, in one such embodimentthe atomic ratio of lithium to the combined amount of Ni, Y, Ti, Zr, Hf,V, Nb, Ta, Mo, W, B, Al, Ga, In, Si, Ge, Sn, P, and Sb is at least about1.5:1, respectively. By way of further example, in one such embodimentthe atomic ratio of lithium to the combined amount of Ni, Y, Ti, Zr, Hf,V, Nb, Ta, Mo, W, B, Al, Ga, In, Si, Ge, Sn, P, and Sb is at least about2:1, respectively. By way of further example, in one such embodiment theatomic ratio of lithium to the combined amount of Ni, Y, Ti, Zr, Hf, V,Nb, Ta, Mo, W, B, Al, Ga, In, Si, Ge, Sn, P, and Sb is at least about2.5:1, respectively. In certain embodiments, the atomic ratio of lithiumto the combined amount of nickel, molybdenum, tungsten and the bleachedstate stabilizing element(s) M in the electrochromic lithium nickeloxide material (e.g., wherein M is Y, Ti, Zr, Hf, V, Nb, Ta, B, Al, Ga,In, Si, Ge, Sn, P, Sb or a combination thereof) will not exceed about4:1, respectively. In some embodiments, therefore, the atomic ratio oflithium to the combined amount of nickel, molybdenum, tungsten and thebleached state stabilizing element(s) M in the electrochromic lithiumnickel oxide material (e.g., wherein M is Y, Ti, Zr, Hf, V, Nb, Ta, B,Al, Ga, In, Si, Ge, Sn, P, Sb or a combination thereof) will be in therange about 0.75:1 to about 3:1, respectively. In some embodiments,therefore, the atomic ratio of lithium to the combined amount of nickel,molybdenum, tungsten and the bleached state stabilizing element(s) M inthe electrochromic lithium nickel oxide material (e.g., wherein M is Y,Ti, Zr, Hf, V, Nb, Ta, B, Al, Ga, In, Si, Ge, Sn, P, Sb or a combinationthereof) will be in the range about 0.9:1 to about 2.5:1, respectively.In some embodiments, therefore, the atomic ratio of lithium to thecombined amount of nickel, molybdenum, tungsten and the bleached statestabilizing element(s) M in the electrochromic lithium nickel oxidematerial (e.g., wherein M is Y, Ti, Zr, Hf, V, Nb, Ta, B, Al, Ga, In,Si, Ge, Sn, P, Sb or a combination thereof) will be in the range about1:1 to about 2.5:1, respectively. In some embodiments, therefore, theatomic ratio of lithium to the combined amount of nickel, molybdenum,tungsten and the bleached state stabilizing element(s) M in theelectrochromic lithium nickel oxide material (e.g., wherein M is Y, Ti,Zr, Hf, V, Nb, Ta, B, Al, Ga, In, Si, Ge, Sn, P, Sb or a combinationthereof) will be in the range about 1.1:1 to about 1.5:1, respectively.In some embodiments, therefore, the atomic ratio of lithium to thecombined amount of nickel, molybdenum, tungsten and the bleached statestabilizing element(s) M in the electrochromic lithium nickel oxidematerial (e.g., wherein M is Y, Ti, Zr, Hf, V, Nb, Ta, B, Al, Ga, In,Si, Ge, Sn, P, Sb or a combination thereof) will be in the range about1.5:1 to about 2:1, respectively. In some embodiments, therefore, theatomic ratio of lithium to the combined amount of nickel, molybdenum,tungsten and the bleached state stabilizing element(s) M in theelectrochromic lithium nickel oxide material (e.g., wherein M is Y, Ti,Zr, Hf, V, Nb, Ta, B, Al, Ga, In, Si, Ge, Sn, P, Sb or a combinationthereof) will be in the range about 2:1 to about 2.5:1, respectively.

In one embodiment, the anodic electrochromic layer comprises one or morebleached state stabilizing elements selected from the group consistingof Group 3, Group 4, Group 5, Group 13, Group 14 and Group 15 elements(IUPAC classification), and combinations thereof in addition tomolybdenum and tungsten. In such embodiments, the relative amounts oflithium, nickel, molybdenum, tungsten and the bleached state stabilizingelement(s) in the electrochromic lithium nickel oxide material arecontrolled such that an atomic ratio of the amount of lithium to thecombined amount of nickel, molybdenum, tungsten and bleached statestabilizing element(s) in the electrochromic lithium nickel oxidematerial may be less than 1.75:1, respectively, when the electrochromiclithium nickel oxide material is in its fully bleached state and thebleached state stabilizing element(s) is/are selected from the groupconsisting of Group 3, Group 4, Group 5, Group 13, Group 14 and Group 15elements, and combinations thereof. For example, in one embodiment, theatomic ratio of lithium to the combined amount of nickel and all Group 6metal(s) and bleached state stabilizing elements, i.e., Li:[Ni+Mo+W+M],in the electrochromic lithium nickel oxide material is less than 1.75:1,respectively, when the electrochromic lithium nickel oxide material isin its fully bleached state and M is a bleached state stabilizingelement selected from the group consisting of Y, Ti, Zr, Hf, V, Nb, Ta,B, Al, Ga, In, Si, Ge, Sn, P, Sb, and combinations thereof; stateddifferently, the ratio of the amount of lithium to the combined amountof Ni, Y, Ti, Zr, Hf, V, Nb, Ta, Mo, W, B, Al, Ga, In, Si, Ge, Sn, P,and Sb, in the electrochromic lithium nickel oxide material is less than1.75:1 (atomic ratio), respectively. By way of further example, in onesuch embodiment the atomic ratio of lithium to the combined amount ofNi, Y, Ti, Zr, Hf, V, Nb, Ta, Mo, W, B, Al, Ga, In, Si, Ge, Sn, P, andSb is less than 1.5:1, respectively, when the electrochromic lithiumnickel oxide material is in its fully bleached state. By way of furtherexample, in one such embodiment the atomic ratio of lithium to thecombined amount of Ni, Y, Ti, Zr, Hf, V, Nb, Ta, Mo, W, B, Al, Ga, In,Si, Ge, Sn, P, and Sb is less than 1.45:1, respectively, when theelectrochromic lithium nickel oxide material is in its fully bleachedstate. By way of further example, in one such embodiment the atomicratio of lithium to the combined amount of Ni, Y, Ti, Zr, Hf, V, Nb, Ta,Mo, W, B, Al, Ga, In, Si, Ge, Sn, P, and Sb is less than 1.4:1,respectively, when the electrochromic lithium nickel oxide material isin its fully bleached state. By way of further example, in one suchembodiment the atomic ratio of lithium to the combined amount of Ni, Y,Ti, Zr, Hf, V, Nb, Ta, Mo, W, B, Al, Ga, In, Si, Ge, Sn, P, and Sb isless than 1.35:1, respectively, when the electrochromic lithium nickeloxide material is in its fully bleached state. By way of furtherexample, in one such embodiment the atomic ratio of lithium to thecombined amount of Ni, Y, Ti, Zr, Hf, V, Nb, Ta, Mo, W, B, Al, Ga, In,Si, Ge, Sn, P, and Sb is less than 1.3:1, respectively, when theelectrochromic lithium nickel oxide material is in its fully bleachedstate. By way of further example, in one such embodiment the atomicratio of lithium to the combined amount of Ni, Y, Ti, Zr, Hf, V, Nb, Ta,Mo, W, B, Al, Ga, In, Si, Ge, Sn, P, and Sb is less than 1.25:1,respectively, when the electrochromic lithium nickel oxide material isin its fully bleached state. By way of further example, in one suchembodiment the atomic ratio of lithium to the combined amount of Ni, Y,Ti, Zr, Hf, V, Nb, Ta, Mo, W, B, Al, Ga, In, Si, Ge, Sn, P, and Sb isless than 1.2:1, respectively, when the electrochromic lithium nickeloxide material is in its fully bleached state. By way of furtherexample, in one such embodiment the atomic ratio of lithium to thecombined amount of Ni, Y, Ti, Zr, Hf, V, Nb, Ta, Mo, W, B, Al, Ga, In,Si, Ge, Sn, P, and Sb is less than 1.1:1, respectively, when theelectrochromic lithium nickel oxide material is in its fully bleachedstate. By way of further example, in one such embodiment the atomicratio of lithium to the combined amount of Ni, Y, Ti, Zr, Hf, V, Nb, Ta,Mo, W, B, Al, Ga, In, Si, Ge, Sn, P, and Sb is less than 1.1,respectively, when the electrochromic lithium nickel oxide material isin its fully bleached state. By way of further example, in one suchembodiment the atomic ratio of lithium to the combined amount of Ni, Y,Ti, Zr, Hf, V, Nb, Ta, Mo, W, B, Al, Ga, In, Si, Ge, Sn, P, and Sb is inthe range of 0.4:1 to 1.5:1, respectively, when the electrochromiclithium nickel oxide material is in its fully bleached state. By way offurther example, in one such embodiment the atomic ratio of lithium tothe combined amount of Ni, Y, Ti, Zr, Hf, V, Nb, Ta, Mo, W, B, Al, Ga,In, Si, Ge, Sn, P, and Sb is in the range of 0.5:1 to 1.45:1,respectively, when the electrochromic lithium nickel oxide material isin its fully bleached state. By way of further example, in one suchembodiment the atomic ratio of lithium to the combined amount of Ni, Y,Ti, Zr, Hf, V, Nb, Ta, Mo, W, B, Al, Ga, In, Si, Ge, Sn, P, and Sb is inthe range of 0.6:1 to 1.4:1, respectively, when the electrochromiclithium nickel oxide material is in its fully bleached state. By way offurther example, in one such embodiment the atomic ratio of lithium tothe combined amount of Ni, Y, Ti, Zr, Hf, V, Nb, Ta, Mo, W, B, Al, Ga,In, Si, Ge, Sn, P, and Sb is in the range of 0.7:1 to 1.35:1,respectively, when the electrochromic lithium nickel oxide material isin its fully bleached state. By way of further example, in one suchembodiment the atomic ratio of lithium to the combined amount of Ni, Y,Ti, Zr, Hf, V, Nb, Ta, Mo, W, B, Al, Ga, In, Si, Ge, Sn, P, and Sb is inthe range of 0.8:1 to 1.35:1, respectively, when the electrochromiclithium nickel oxide material is in its fully bleached state. By way offurther example, in one such embodiment the atomic ratio of lithium tothe combined amount of Ni, Y, Ti, Zr, Hf, V, Nb, Ta, Mo, W, B, Al, Ga,In, Si, Ge, Sn, P, and Sb is in the range of 0.9:1 to 1.35:1,respectively, when the electrochromic layer is in its fully bleachedstate.

In those embodiments in which the anodic electrochromic layer comprisesone or more bleached state stabilizing elements M selected from thegroup consisting of Group 3, Group 4, Group 5, Group 13, Group 14 andGroup 15 elements and combinations thereof in addition to molybdenumand/or tungsten, increasing the amount of the Group 6 metal(s) andbleached state stabilizing element(s) relative to the amount of nickelin the electrochromic layer increases the stability and bleached statevoltage of the material but it also tends to decrease its volumetriccharge capacity. Anodic electrochromic lithium nickel oxide materialhaving large amounts of molybdenum, tungsten, and bleached statestabilizing element(s) relative to nickel, such as those in which theatomic ratio of the combined amount of molybdenum, tungsten and bleachedstate stabilizing element(s) M to the combined amount of nickel,molybdenum, tungsten and bleached state stabilizing elements M (i.e.,[Mo+W+M]:[Ni+Mo+W+M]) is greater than about 0.8:1, respectively, tend tohave stable fully bleached states, but sub-optimal charge capacities anddarkened state transmissivities. Thus, in certain embodiments it ispreferred that the atomic ratio of the combined amount of molybdenum,tungsten and bleached state stabilizing element(s) M to the combinedamount of nickel, molybdenum, tungsten and bleached state stabilizingelements M in the electrochromic lithium nickel oxide material be lessthan about 0.8:1 (i.e., [Mo+W+M]:[Ni+Mo+W+M]), respectively. Forexample, in one such embodiment the atomic ratio of the combined amountof molybdenum, tungsten and bleached state stabilizing elements M to thecombined amount of nickel, molybdenum, tungsten and bleached statestabilizing elements M in the electrochromic lithium nickel oxidematerial is less than about 0.7:1 (i.e., [Mo+W+M]:[Ni+Mo+W+M]),respectively. By way of further example, in one such embodiment theatomic ratio of the combined amount of molybdenum, tungsten and bleachedstate stabilizing element(s) M to the combined amount of nickel,molybdenum, tungsten and bleached state stabilizing element(s) M in theelectrochromic lithium nickel oxide material is less than about 0.6:1(i.e., [Mo+W+M]:[Ni+Mo+W+M]), respectively. By way of further example,in one such embodiment the atomic ratio of the combined amount ofmolybdenum, tungsten and bleached state stabilizing element(s) M to thecombined amount of nickel, molybdenum, tungsten and bleached statestabilizing element(s) M in the electrochromic lithium nickel oxidematerial is less than about 0.5:1 (i.e., [Mo+W+M]:[Ni+Mo+W+M]),respectively. By way of further example, in one such embodiment theatomic ratio of the combined amount of molybdenum, tungsten and bleachedstate stabilizing element(s) M to the combined amount of nickel,molybdenum, tungsten and bleached state stabilizing element(s) M in theelectrochromic layer is less than about 0.4:1 (i.e.,[Mo+W+M]:[Ni+Mo+W+M]), respectively.

Conversely, anodic electrochromic layers having small amounts ofmolybdenum, tungsten, and bleached state stabilizing element(s) Mrelative to nickel, such as those in which the atomic ratio of thecombined amount of molybdenum, tungsten, and bleached state stabilizingelements M (wherein M is Y, Ti, Zr, Hf, V, Nb, Ta, B, Al, Ga, In, Si,Ge, Sn, P, Sb or a combination thereof) to the combined amount ofnickel, molybdenum, tungsten and bleached state stabilizing elements M(i.e., [Mo+W+M]:[Ni+Mo+W+M]) is less than about 0.025:1, respectively,tend to have relatively high charge capacities but less stable fullybleached states. Thus, in certain embodiments it is preferred that theratio (atomic) of the combined amount of molybdenum, tungsten andbleached state stabilizing element(s) M to the combined amount ofnickel, molybdenum, tungsten and bleached state stabilizing elements Min the electrochromic lithium nickel oxide material be greater thanabout 0.03:1 (i.e., [Mo+W+M]:[Ni+Mo+W+M]), respectively. For example, inone such embodiment the atomic ratio of the combined amount ofmolybdenum and tungsten to the combined amount of nickel, molybdenum,tungsten and bleached state stabilizing elements M in the electrochromiclithium nickel oxide material is greater than about 0.04:1 (i.e.,[Mo+W+M]:[Ni+Mo+W+M]), respectively. By way of further example, in onesuch embodiment the atomic ratio of the combined amount of molybdenum,tungsten and bleached state stabilizing element(s) M to the combinedamount of nickel, molybdenum, tungsten and bleached state stabilizingelements M in the electrochromic lithium nickel oxide material isgreater than about 0.05:1 (i.e., [Mo+W+M]:[Ni+Mo+W+M]), respectively. Byway of further example, in one such embodiment the atomic ratio of thecombined amount of molybdenum, tungsten and bleached state stabilizingelement(s) M to the combined amount of nickel, molybdenum, tungsten andbleached state stabilizing elements M in the electrochromic lithiumnickel oxide material is greater than about 0.075:1 (i.e.,[Mo+W+M]:[Ni+Mo+W+M]), respectively. By way of further example, in onesuch embodiment the atomic ratio of the combined amount of molybdenum,tungsten and bleached state stabilizing element(s) M to the combinedamount of nickel, molybdenum, tungsten and bleached state stabilizingelements M in the electrochromic layer is greater than about 0.1:1(i.e., [Mo+W+M]:[Ni+Mo+W+M]), respectively.

In those embodiments in which the anodic electrochromic layer comprisesone or more bleached state stabilizing elements M selected from thegroup consisting of Group 3, Group 4, Group 5, Group 13, Group 14 andGroup 15 elements and combinations thereof in addition to molybdenumand/or tungsten, the ratio (atomic) of the combined amount ofmolybdenum, tungsten and bleached state stabilizing elements to thecombined amount of nickel, molybdenum, tungsten and bleached statestabilizing elements M (wherein M is Y, Ti, Zr, Hf, V, Nb, Ta, B, Al,Ga, In, Si, Ge, Sn, P, Sb or a combination thereof) in the anodicelectrochromic lithium nickel oxide material will typically be in therange of about 0.025:1 to about 0.8:1 ([Mo+W+M]:[Ni+Mo+W+M]),respectively. For example, in one such embodiment the atomic ratio ofthe combined amount of molybdenum, tungsten and bleached statestabilizing element(s) M to the combined amount nickel, molybdenum,tungsten and bleached state stabilizing elements M in the anodicelectrochromic lithium nickel oxide material will typically be in therange of about 0.05:1 and about 0.7:1 ([Mo+W+M]:[Ni+Mo+W+M]),respectively. By way of further example, in one such embodiment theatomic ratio of the combined amount of molybdenum and tungsten to thecombined amount nickel, molybdenum, tungsten and bleached statestabilizing elements M in the anodic electrochromic layer will typicallybe in the range of about 0.075:1 and about 0.6:1 ([Mo+W+M]:[Ni+Mo+W+M]),respectively.

In one embodiment, the anodic electrochromic layer has a bleached statevoltage that is at least 2V. For example, in one embodiment the anodicelectrochromic lithium oxide material has a bleached state voltage of atleast 2.25V. By way of further example, in one embodiment the anodicelectrochromic lithium oxide material has a bleached state voltage of atleast 2.5V. By way of further example, in one embodiment the anodicelectrochromic lithium oxide material has a bleached state voltage of atleast 2.75V. By way of further example, in one embodiment the anodicelectrochromic lithium oxide material has a bleached state voltage of atleast 3V. By way of further example, in one embodiment the anodicelectrochromic lithium oxide material has a bleached state voltage of atleast 3.25V. By way of further example, in one embodiment the anodicelectrochromic lithium oxide material has a bleached state voltage of atleast 3.5V.

Electrochromic Stacks and Devices

FIG. 1 depicts a cross-sectional structural diagram of electrochromicstructure 1 having an anodic electrochromic layer comprising lithium,nickel, and at least one bleached state stabilizing element inaccordance with one embodiment of the present invention. Moving outwardfrom the center, electrochromic device 1 comprises an ion conductorlayer 10. Anode layer 20 (an anodic electrochromic layer comprisinglithium, nickel, and titanium, zirconium, or hafnium and optionally oneor more bleached state stabilizing element as described in greaterdetail elsewhere herein) is on one side of and in contact with a firstsurface of ion conductor layer 10. Cathode layer 21 is on the other sideof and in contact with a second surface of ion conductor layer 10. Thecentral structure, that is, layers 20, 10, 21, is positioned betweenfirst and second electrically conductive layers 22 and 23 which, inturn, are arranged against outer substrates 24, 25. Elements 22, 20, 10,21, and 23 are collectively referred to as an electrochromic stack 28.

Ion conductor layer 10 serves as a medium through which lithium ions aretransported (in the manner of an electrolyte) when the electrochromicdevice transforms between the bleached state and the darkened state. Ionconductor layer 10 comprises an ion conductor material and may betransparent or non-transparent, colored or non-colored, depending on theapplication. Preferably, ion conductor layer 10 is highly conductive tolithium ions and has sufficiently low electron conductivity thatnegligible electron transfer takes place during normal operation.

Some non-exclusive examples of electrolyte types are: solid polymerelectrolytes (SPE), such as poly(ethylene oxide) with a dissolvedlithium salt; gel polymer electrolytes (GPE), such as mixtures ofpoly(methyl methacrylate) and propylene carbonate with a lithium salt;composite gel polymer electrolytes (CGPE) that are similar to GPE's butwith an addition of a second polymer such a poly(ethylene oxide), andliquid electrolytes (LE) such as a solvent mixture of ethylenecarbonate/diethyl carbonate with a lithium salt; and compositeorganic-inorganic electrolytes (CE), comprising an LE with an additionof titania, silica or other oxides. Some non-exclusive examples oflithium salts used are LiTFSI (lithium bis(trifluoromethane)sulfonimide), LiBF₄ (lithium tetrafluoroborate), LiPF₆ (lithiumhexafluorophosphate), LiAsF₆ (lithium hexafluoro arsenate), LiCF₃SO₃(lithium trifluoromethane sulfonate), LiB(C₆F₅)₄ (lithiumperfluorotetraphenylboron) and LiClO₄ (lithium perchlorate). Additionalexamples of suitable ion conductor layers include silicates, tungstenoxides, tantalum oxides, niobium oxides, and borates. The silicon oxidesinclude silicon-aluminum-oxide. These materials may be doped withdifferent dopants, including lithium. Lithium doped silicon oxidesinclude lithium silicon-aluminum-oxide. In some embodiments, the ionconductor layer comprises a silicate-based structure. In otherembodiments, suitable ion conductors particularly adapted for lithiumion transport include, but are not limited to, lithium silicate, lithiumaluminum silicate, lithium aluminum borate, lithium aluminum fluoride,lithium borate, lithium nitride, lithium zirconium silicate, lithiumniobate, lithium borosilicate, lithium phosphosilicate, and other suchlithium-based ceramic materials, silicas, or silicon oxides, includinglithium silicon-oxide.

The thickness of the ion conductor layer 10 will vary depending on thematerial. In some embodiments using an inorganic ion conductor the ionconductor layer 10 is about 250 nm to 1 nm thick, preferably about 50 nmto 5 nm thick. In some embodiments using an organic ion conductor, theion conductor layer is about 1000000 nm to 1000 nm thick or about 250000nm to 10000 nm thick. The thickness of the ion conductor layer is alsosubstantially uniform. In one embodiment, a substantially uniform ionconductor layer varies by not more than about +/−10% in each of theaforementioned thickness ranges. In another embodiment, a substantiallyuniform ion conductor layer varies by not more than about +/−5% in eachof the aforementioned thickness ranges. In another embodiment, asubstantially uniform ion conductor layer varies by not more than about+/−3% in each of the aforementioned thickness ranges.

Anode layer 20 is an anodic electrochromic layer comprising lithium,nickel, and at least one Group 6 metal selected from molybdenum andtungsten as described in greater detail elsewhere herein. In oneembodiment, cathode layer 21 is an electrochromic layer. For example,cathode layer 21 may comprise an electrochromic oxide based on tungsten,molybdenum, niobium, titanium, and/or bismuth. In an alternativeembodiment, cathode layer 21 is a non-electrochromic counter-electrodefor anode layer 20 such as cerium-oxide.

The thickness of anode layer 20 and cathode layer 21 will depend uponthe electrochromic material selected for the electrochromic layer andthe application. In some embodiments, anode layer 20 will have athickness in the range of about 25 nm to about 2000 nm. For example, inone embodiment anode layer 20 has a thickness of about 50 nm to about2000 nm. By way of further example, in one embodiment anode layer 20 hasa thickness of about 25 nm to about 1000 nm. By way of further example,in one such embodiment, anode layer 20 has an average thickness betweenabout 100 nm and about 700 nm. In some embodiments, anode layer 20 has athickness of about 250 nm to about 500 nm. Cathode layer 21 willtypically have thicknesses in the same ranges as those stated for anodelayer 20.

In one embodiment, anode layer 20 and cathode layer 21 are inelectrochemically and optically matched (EOM) states. For example, whenthe cathode is a W-oxide film having a thickness of about 400 nm and anarea charge capacity of 27 mC/cm², a lithium tungsten nickel oxide filmhaving a thickness of about 250 nm and the a charge capacity of 27mC/cm² over a cell voltage of about 1.7V (where 0V is the fully bleachedstate of both anode and cathode).

Electrically conductive layer 22 is in electrical contact with oneterminal of a power supply (not shown) via bus bar 26 and electricallyconductive layer 23 is in electrical contact with the other terminal ofa power supply (not shown) via bus bar 27 whereby the transmissivity ofelectrochromic device 10 may be changed by applying a voltage pulse toelectrically conductive layers 22 and 23. The pulse causes electrons andions to move between anode layer 20 and cathode layer 21 and, as aresult, the anode layer 20 and, optionally, cathode layer 21 change (s)optical states, thereby switching electrochromic structure 1 from a moretransmissive state to a less transmissive state, or from a lesstransmissive state to a more transmissive state. In one embodiment,electrochromic structure 1 is transparent before the voltage pulse andless transmissive (e.g., more reflective or colored) after the voltagepulse or vice versa.

Referring again to FIG. 1, the power supply (not shown) connected to busbars 26, 27 is typically a voltage source with optional current limitsor current control features and may be configured to operate inconjunction with local thermal, photosensitive or other environmentalsensors. The voltage source may also be configured to interface with anenergy management system, such as a computer system that controls theelectrochromic device according to factors such as the time of year,time of day, and measured environmental conditions. Such an energymanagement system, in conjunction with large area electrochromic devices(e.g., an electrochromic architectural window), can dramatically lowerthe energy consumption of a building.

At least one of the substrates 24, 25 is preferably transparent, inorder to reveal the electrochromic properties of the stack 28 to thesurroundings. Any material having suitable optical, electrical, thermal,and mechanical properties may be used as first substrate 24 or secondsubstrate 25. Such substrates include, for example, glass, plastic,metal, and metal coated glass or plastic. Non-exclusive examples ofpossible plastic substrates are polycarbonates, polyacrylics,polyurethanes, urethane carbonate copolymers, polysulfones, polyimides,polyacrylates, polyethers, polyester, polyethylenes, polyalkenes,polyimides, polysulfides, polyvinylacetates and cellulose-basedpolymers. If a plastic substrate is used, it may be barrier protectedand abrasion protected using a hard coat of, for example, a diamond-likeprotection coating, a silica/silicone anti-abrasion coating, or thelike, such as is well known in the plastic glazing art. Suitable glassesinclude either clear or tinted soda lime glass, chemically tempered sodalime glass, heat strengthened soda lime glass, tempered glass, orborosilicate glass. In some embodiments of electrochromic structure 1with glass, e.g. soda lime glass, used as first substrate 24 and/orsecond substrate 25, there is a sodium diffusion barrier layer (notshown) between first substrate 24 and first electrically conductivelayer 22 and/or between second substrate 25 and second electricallyconductive layer 23 to prevent the diffusion of sodium ions from theglass into first and/or second electrically conductive layer 23. In someembodiments, second substrate 25 is omitted.

In one preferred embodiment of the invention, first substrate 24 andsecond substrate 25 are each float glass. In certain embodiments forarchitectural applications, this glass is at least 0.5 meters by 0.5meters, and can be much larger, e.g., as large as about 3 meters by 4meters. In such applications, this glass is typically at least about 2mm thick and more commonly 4-6 mm thick.

Independent of application, the electrochromic devices of the presentinvention may have a wide range of sizes. In general, it is preferredthat the electrochromic device comprise a substrate having a surfacewith a surface area of at least 0.001 meter². For example, in certainembodiments, the electrochromic device comprises a substrate having asurface with a surface area of at least 0.01 meter². By way of furtherexample, in certain embodiments, the electrochromic device comprises asubstrate having a surface with a surface area of at least 0.1 meter².By way of further example, in certain embodiments, the electrochromicdevice comprises a substrate having a surface with a surface area of atleast 1 meter². By way of further example, in certain embodiments, theelectrochromic device comprises a substrate having a surface with asurface area of at least 5 meter². By way of further example, in certainembodiments, the electrochromic device comprises a substrate having asurface with a surface area of at least 10 meter².

At least one of the two electrically conductive layers 22, 23 is alsopreferably transparent in order to reveal the electrochromic propertiesof the stack 28 to the surroundings. In one embodiment, electricallyconductive layer 23 is transparent. In another embodiment, electricallyconductive layer 22 is transparent. In another embodiment, electricallyconductive layers 22, 23 are each transparent. In certain embodiments,one or both of the electrically conductive layers 22, 23 is inorganicand/or solid. Electrically conductive layers 22 and 23 may be made froma number of different transparent materials, including transparentconductive oxides, thin metallic coatings, networks of conductive nanoparticles (e.g., rods, tubes, dots) conductive metal nitrides, andcomposite conductors. Transparent conductive oxides include metal oxidesand metal oxides doped with one or more metals. Examples of such metaloxides and doped metal oxides include indium oxide, indium tin oxide,doped indium oxide, tin oxide, doped tin oxide, zinc oxide, aluminumzinc oxide, doped zinc oxide, ruthenium oxide, doped ruthenium oxide andthe like. Transparent conductive oxides are sometimes referred to as(TCO) layers. Thin metallic coatings that are substantially transparentmay also be used. Examples of metals used for such thin metalliccoatings include gold, platinum, silver, aluminum, nickel, and alloys ofthese. Examples of transparent conductive nitrides include titaniumnitrides, tantalum nitrides, titanium oxynitrides, and tantalumoxynitrides. Electrically conducting layers 22 and 23 may also betransparent composite conductors. Such composite conductors may befabricated by placing highly conductive ceramic and metal wires orconductive layer patterns on one of the faces of the substrate and thenover-coating with transparent conductive materials such as doped tinoxides or indium tin oxide. Ideally, such wires should be thin enough asto be invisible to the naked eye (e.g., about 100 μm or thinner).Non-exclusive examples of electron conductors 22 and 23 transparent tovisible light are thin films of indium tin oxide (ITO), tin oxide, zincoxide, titanium oxide, n- or p-doped zinc oxide and zinc oxyfluoride.Metal-based layers, such as ZnS/Ag/ZnS and carbon nanotube layers havebeen recently explored as well. Depending on the particular application,one or both electrically conductive layers 22 and 23 may be made of orinclude a metal grid.

The thickness of the electrically conductive layer may be influenced bythe composition of the material comprised within the layer and itstransparent character. In some embodiments, electrically conductivelayers 22 and 23 are transparent and each have a thickness that isbetween about 1000 nm and about 50 nm. In some embodiments, thethickness of electrically conductive layers 22 and 23 is between about500 nm and about 100 nm. In other embodiments, the electricallyconductive layers 22 and 23 each have a thickness that is between about400 nm and about 200 nm. In general, thicker or thinner layers may beemployed so long as they provide the necessary electrical properties(e.g., conductivity) and optical properties (e.g., transmittance). Forcertain applications it will generally be preferred that electricallyconductive layers 22 and 23 be as thin as possible to increasetransparency and to reduce cost.

Referring again to FIG. 1, the function of the electrically conductivelayers is to apply the electric potential provided by a power supplyover the entire surface of the electrochromic stack 28 to interiorregions of the stack. The electric potential is transferred to theconductive layers though electrical connections to the conductivelayers. In some embodiments, bus bars, one in contact with firstelectrically conductive layer 22 and one in contact with secondelectrically conductive layer 23 provide the electrical connectionbetween the voltage source and the electrically conductive layers 22 and23.

In one embodiment, the sheet resistance, R_(s), of the first and secondelectrically conductive layers 22 and 23 is about 500Ω/□ to 1Ω/□. Insome embodiments, the sheet resistance of first and second electricallyconductive layers 22 and 23 is about 100Ω/□ to 5Ω/□. In general, it isdesirable that the sheet resistance of each of the first and secondelectrically conductive layers 22 and 23 be about the same. In oneembodiment, first and second electrically conductive layers 22 and 23each have a sheet resistance of about 20Ω/□ to about 8 Ω/□.

To facilitate more rapid switching of electrochromic structure 1 from astate of relatively greater transmittance to a state of relativelylesser transmittance, or vice versa, at least one of electricallyconductive layers 22, 23 may have a sheet resistance, R_(s), to the flowof electrons through the layer that is non-uniform. For example, in oneembodiment only one of first and second electrically conductive layers22, 23 has a non-uniform sheet resistance to the flow of electronsthrough the layer. Alternatively, first electrically conductive layer 22and second electrically conductive layer 23 may each have a non-uniformsheet resistance to the flow of electrons through the respective layers.Without being bound by any particular theory, it is presently believedthat spatially varying the sheet resistance of electrically conductivelayer 22, spatially varying the sheet resistance of electricallyconductive layer 23, or spatially varying the sheet resistance ofelectrically conductive layer 22 and electrically conductive layer 23improves the switching performance of the device by controlling thevoltage drop in the conductive layer to provide uniform potential dropor a desired non-uniform potential drop across the device, over the areaof the device as more fully described in WO2012/109494.

FIG. 2 depicts a cross-sectional structural diagram of electrochromicstructure 1 according to an alternative embodiment of the presentinvention. Moving outward from the center, electrochromic structure 1comprises an ion conductor layer 10. Anode layer 20 (an anodicelectrochromic layer comprising lithium, nickel, and at least one Group6 metal as described in greater detail elsewhere herein) is on one sideof and in contact with a first surface of ion conductor layer 10, andcathode layer 21 is on the other side of and in contact with a secondsurface of ion conductor layer 10. First and second current modulatingstructures 30 and 31, in turn, are adjacent first and secondelectrically conductive layers 22 and 23, respectively, which arearranged against outer substrates 24, 25, respectively.

To facilitate more rapid switching of electrochromic structure 1 from astate of relatively greater transmittance to a state of relativelylesser transmittance, or vice versa, first current modulating structure30, second current modulating structure 31 or both first and secondcurrent modulating structures 30 and 31 comprise a resistive material(e.g., a material having a resistivity of at least about 10⁴ Ω·cm). Inone embodiment at least one of first and second current modulatingstructures 30, 31 has a non-uniform cross-layer resistance, R_(C), tothe flow of electrons through the structure. In one such embodiment onlyone of first and second current modulating structures 30, 31 has anon-uniform cross-layer resistance, R_(C), to the flow of electronsthrough the layer. Alternatively, and more typically, first currentmodulating structure 30 and second current modulating structure 31 eachhave a non-uniform cross-layer resistance, R_(C), to the flow ofelectrons through the respective layers. Without being bound by anyparticular theory, it is presently believed that spatially varying thecross-layer resistance, R_(C), of first current modulating structure 30and second current modulating structure 31, spatially varying thecross-layer resistance, R_(C), of the first current modulating structure30, or spatially varying the cross-layer resistance, R_(C), of thesecond current modulating structure 31 improves the switchingperformance of the device by providing a more uniform potential drop ora desired non-uniform potential drop across the device, over the area ofthe device.

In one exemplary embodiment, current modulating structure 30 and/or 31is a composite comprising at least two materials possessing differentconductivities. For example, in one embodiment the first material is aresistive material having a resistivity in the range of about 10⁴ Ω·cmto 10¹⁰ Ω·cm and the second material is an insulator. By way of furtherexample, in one embodiment the first material is a resistive materialhaving a resistivity of at least 10⁴ Ω·cm and the second material has aresistivity that exceeds the resistivity of the first by a factor of atleast 10². By way of further example, in one embodiment the firstmaterial is a resistive material having a resistivity of at least 10⁴Ω·cm and the second material has a resistivity that exceeds theresistivity of the first by a factor of at least 10³. By way of furtherexample, in one embodiment the first material is a resistive materialhaving a resistivity of at least 10⁴ Ω·cm and the second material has aresistivity that exceeds the resistivity of the first by a factor of atleast 10⁴. By way of further example, in one embodiment the firstmaterial is a resistive material having a resistivity of at least 10⁴Ω·cm and the second material has a resistivity that exceeds theresistivity of the first by a factor of at least 10⁵. By way of furtherexample, in one embodiment, at least one of current modulatingstructures 30, 31 comprises a first material having a resistivity in therange of 10⁴ to 10¹⁰ Ω·cm and a second material that is an insulator orhas a resistivity in the range of 10¹⁰ to 10¹⁴ Ω·cm. By way of furtherexample, in one embodiment, at least one of current modulatingstructures 30, 31 comprises a first material having a resistivity in therange of 10⁴ to 10¹⁰ cm and a second material having a resistivity inthe range of 10¹⁰ to 10¹⁴ Ω·cm wherein the resistivities of the firstand second materials differ by a factor of at least 10³. By way offurther example, in one embodiment, at least one of current modulatingstructures 30, 31 comprises a first material having a resistivity in therange of 10⁴ to 10¹⁰ Ω·cm and a second material having a resistivity inthe range of 10¹⁰ to 10¹⁴ Ω·cm wherein the resistivities of the firstand second materials differ by a factor of at least 10⁴. By way offurther example, in one embodiment, at least one of current modulatingstructures 30, 31 comprises a first material having a resistivity in therange of 10⁴ to 10¹⁰ Ω·cm and a second material having a resistivity inthe range of 10¹⁰ to 10¹⁴ Ω·cm wherein the resistivities of the firstand second materials differ by a factor of at least 10⁵. In each of theforegoing exemplary embodiments, each of current modulating structures30, 31 may comprise a first material having a resistivity in the rangeof 10⁴ to 10¹⁰ Ω·cm and a second material that is insulating.

Depending upon the application, the relative proportions of the firstand second materials in current modulating structure 30 and/or 31 mayvary substantially. In general, however, the second material (i.e., theinsulating material or material having a resistivity of at least 10¹⁰Ω·cm) constitutes at least about 5 vol % of at least one of currentmodulating structures 30, 31. For example, in one embodiment the secondmaterial constitutes at least about 10 vol % of at least one of currentmodulating structures 30, 31. By way of further example, in oneembodiment the second material constitutes at least about 20 vol % of atleast one of current modulating structures 30, 31. By way of furtherexample, in one embodiment the second material constitutes at leastabout 30 vol % of at least one of current modulating structures 30, 31.By way of further example, in one embodiment the second materialconstitutes at least about 40 vol % of at least one of currentmodulating structures 30, 31. In general, however, the second materialwill typically not constitute more than about 70 vol % of either ofcurrent modulating structures 30, 31. In each of the foregoingembodiments and as previously discussed, the second material may have aresistivity in the range of 10¹⁰ to 10¹⁴ Ω·cm and the resistivities ofthe first and second materials (in either or both of current modulatingstructures 30, 31) may differ by a factor of at least 10³.

In general, first and second current modulating structures 30, 31 maycomprise any material exhibiting sufficient resistivity, opticaltransparency, and chemical stability for the intended application. Forexample, in some embodiments, current modulating structures 30, 31 maycomprise a resistive or insulating material with high chemicalstability. Exemplary insulator materials include alumina, silica, poroussilica, fluorine doped silica, carbon doped silica, silicon nitride,silicon oxynitride, hafnia, magnesium fluoride, magnesium oxide,poly(methyl methacrylate) (PMMA), polyimides, polymeric dielectrics suchas polytetrafluoroethylene (PTFE) and silicones. Exemplary resistivematerials include zinc oxide, zinc sulfide, titanium oxide, and gallium(III) oxide, yttrium oxide, zirconium oxide, aluminum oxide, indiumoxide, stannic oxide and germanium oxide. In one embodiment, one or bothof first and second current modulating structures 30, 31 comprise one ormore of such resistive materials. In another embodiment, one or both offirst and second current modulating structures 30, 31 comprise one ormore of such insulating materials. In another embodiment, one or both offirst and second current modulating structures 30, 31 comprise one ormore of such resistive materials and one or more of such insulatingmaterials.

The thickness of current modulating structures 30, 31 may be influencedby the composition of the material comprised by the structures and itsresistivity and transmissivity. In some embodiments, current modulatingstructures 30 and 31 are transparent and each have a thickness that isbetween about 50 nm and about 1 micrometer. In some embodiments, thethickness of current modulating structures 30 and 31 is between about100 nm and about 500 nm. In general, thicker or thinner layers may beemployed so long as they provide the necessary electrical properties(e.g., conductivity) and optical properties (e.g., transmittance). Forcertain applications it will generally be preferred that currentmodulating structures 30 and 31 be as thin as possible to increasetransparency and to reduce cost.

Anodic Electrochromic Layer Preparation

In one embodiment, anodic electrochromic lithium nickel oxidecompositions may be prepared from a liquid mixture containing lithium,nickel, at least one Group 6 metal, and optionally one or more bleachedstate stabilizing element(s) as previously described. For example, inone embodiment, the liquid mixture is deposited on the surface of asubstrate to form a film comprising lithium, nickel, at least one Group6 metal, and optionally at least one bleached state stabilizing elementand the deposited film is then treated to form an anodic electrochromiclithium nickel oxide layer containing lithium, nickel, the Group 6metal(s) (and optionally one or more bleached state stabilizingelements). In such embodiments, the relative amounts of lithium, nickel,molybdenum and tungsten and bleached state stabilizing element(s) in theliquid mixture are controlled to provide an atomic ratio of lithium tothe combined amount of nickel and Group 6 metal(s) and bleached statestabilizing element(s) in the deposited film is generally at least about0.4:1, respectively, as previously described.

The liquid mixture may be prepared by combining, in a solvent system, asource of lithium, nickel, and at least one Group 6 metal. In general,the source (starting) materials for each of the lithium, nickel andGroup 6 metal(s) comprised by the liquid mixture are soluble ordispersible in the liquid mixture solvent system and provide a source ofmetal(s) or metal oxide(s) for the lithium nickel oxide film. In oneembodiment, the liquid mixture is passed through a 0.2 micron filterprior to the coating step.

The lithium component of the liquid mixture may be derived from a rangeof soluble or dispersible lithium-containing source (starting) materialsthat chemically or thermally decompose to provide a source of lithium.For example, the source of lithium for the liquid mixture may comprise alithium derivative of an organic compound (e.g., an organolithiumcompound) or a lithium salt of an inorganic anion such as hydroxide,carbonate, nitrate, sulfate, peroxide, bicarbonate and the like.

A wide variety of lithium derivatives of organic compounds are describedin the literature and are useful as lithium sources for the liquidmixtures of this invention. They include lithium derivatives of alkanes(alkyl lithium compounds), aromatic compounds (aryl lithium compounds),olefins (vinyl or allyl lithium compounds), acetylenes (lithiumacetylide compounds), alcohols (lithium alkoxide compounds), amines,(lithium amide compounds), thiols (lithium thiolate compounds),carboxylic acids (lithium carboxylate compounds) and β-diketones(β-diketonate compounds). Since the role of the lithium compound is toprovide a soluble source of lithium ion in the lithium nickel oxidelayer, the organic portion of the organo-lithium compound is removedduring processing; it preferred to utilize the simple, low cost, andreadily available organo-lithium compounds. It is further preferred thatthe organolithium compound be one that is not pyrophoric when exposed toair; this property limits but does not exclude the use of alkyl, aryl,vinyl, allyl, acetylide organolithium reagents as lithium sources in theliquid mixtures of this invention. In one embodiment, the source(starting) material for the lithium component of the liquid mixture is alithium amide compound corresponding to the formula LiNR¹R² wherein R¹and R² are hydrocarbyl, substituted hydrocarbyl, or silyl, andoptionally, R¹ and R² and the nitrogen atom to which they are bonded mayform a heterocycle.

In an alternative embodiment, the source (starting) material for thelithium component of the liquid mixture is a lithium alkoxidecorresponding to the formula LiOR wherein R is hydrocarbyl, substitutedhydrocarbyl, or optionally substituted silyl. In one such embodiment,the source (starting) material for the lithium component of the liquidmixture is a lithium alkoxide corresponding to the formula LiOR whereinR is optionally substituted alkyl or aryl. For example, in one suchembodiment, R is linear, branched or cyclic alkyl. By way of furtherexample, in one such embodiment, R is 2-dimethylaminoethyl. By way offurther example, in one such embodiment, R is 2-methoxyethyl. By way offurther example, in one such embodiment, R is optionally substitutedaryl. In another embodiment, the source (starting) material for thelithium component of the liquid mixture is a lithium carboxylatecorresponding to the formula LiOC(O)R¹ wherein R¹ is hydrogen,hydrocarbyl, substituted hydrocarbyl, heterocyclo or optionallysubstituted silyl. For example, in one such embodiment R¹ ismethyl(lithium acetate). By way of further example, in one suchembodiment, R¹ is linear or branched alkyl. By way of further example,in one such embodiment, R¹ is cyclic or polycyclic. By way of furtherexample, in one such embodiment, R¹ is optionally substituted aryl. Inanother embodiment, the source (starting) material for the lithiumcomponent of the liquid mixture is a lithium β-diketonate correspondingto the formula

Wherein R¹⁰ and R¹¹ are independently hydrocarbyl, substitutedhydrocarbyl, or optionally substituted silyl. For example, in one suchembodiment, R¹⁰ and R¹¹ are independently linear or branched alkyl. Byway of further example, in one such embodiment, R¹⁰ and R¹¹ areindependently cyclic or polycyclic.

In one embodiment, the source (starting) material for the lithiumcomponent of the liquid mixture comprises a lithium salt of an anioncontaining nickel or a bleached state-stabilizing element. For example,in one such embodiment, the source (starting) material for the lithiumcomponent of the liquid mixture comprises a lithium salt of apolyoxometallate or a Keggin anion, e.g., a heteropolytungstate or aheteropolymolybdate. Alternatively, in one such embodiment, the source(starting) material for the lithium component of the liquid mixturecomprises a lithium salt, or an adduct of a lithium salt such as anetherate of a lithium salt, of an anionic coordination complex of nickeland/or a bleached state stabilizing element. For example, in one suchembodiment, the lithium salt is a lithium salt of a coordination complexcorresponding to the formula [M⁴(OR²)₄]⁻, [M⁵(OR²)₅]⁻, [M⁶(OR²)₆]⁻, or[L_(n)NiX¹X²X³]⁻ where

L is a neutral mono- or polydentate Lewis base ligand

M⁴ is B, Al, Ga, or Y,

M⁵ is Ti, Zr, or Hf,

M⁶ is Nb or Ta,

n is the number of neutral ligands, L, that are coordinated to the Nicenter, and

each R² is independently hydrocarbyl, substituted hydrocarbyl, orsubstituted or unsubstituted hydrocarbyl silyl,

X¹, X², and X³ are independently an anionic organic or inorganic ligand.

In one such embodiment, X¹, X², and X³ are independently halide,alkoxide, diketonate, amide and any two L or X ligands can be joinedtethered via a bridging moiety to form a chelating ligands.

The nickel component of the liquid mixture may be derived from a rangeof soluble or dispersible nickel-containing source (starting) materialsthat chemically or thermally decompose to provide a source of nickel.For example, the source of nickel for the liquid mixture may comprise anickel derivative of an organic compound (e.g., an organonickelcompound) or a nickel salt of an inorganic anion such as hydroxide,carbonate, hydroxycarbonate, nitrate, sulfate, or hybrids comprisingboth organic and inorganic ligands.

A wide variety of organonickel compounds are described in the literatureand are useful as nickel sources for the liquid mixtures of thisinvention. In a preferred embodiment, the source material is dissolvedin the liquid mixture to form a homogeneous solution that is filterablethrough a 0.2 micron filter. For example, in one embodiment the nickelsource is a zero valent organonickel compound. Suitable zero valentorganonickel compounds include bis(cyclooctadiene)Ni.

More commonly, organonickel compounds where the nickel center is in aformal oxidation state of 2+ (Ni(II)) are used as sources of nickel inthe liquid mixtures of this invention. Exemplary Ni(II) complexesfurther organic-ligand stabilized Ni(II) complexes corresponding to theformula L_(n)NiX⁴X⁵ wherein L is a neutral Lewis base ligand, n is thenumber of neutral Lewis ligands coordinated to the Ni center, and X⁴ andX⁵ are independently an organic or inorganic anionic ligand. Forexample, in one such embodiment, the nickel source corresponds to theformula L_(n)NiX⁴X⁵ wherein each L is independently a Lewis base ligandsuch as amine, pyridine, water, THF or phosphine and X⁴ and X⁵ areindependently a hydride, alkyl, alkoxide, allyl, diketonate, amide orcarboxylate ligand and any two L or X ligands can be joined via abridging moiety to form a chelating ligand. Exemplary Ni(II) complexesinclude Ni(II) complexes such as bis(cyclopentadienyl)Ni(II) complexes,Ni(II) allyl complexes including mixed cyclopentadienylNI(II) allylcomplexes, bis(aryl)N(II) complexes such as bis(mesityl)Ni(II),bis(acetate)Ni(II), bis(2-ethylhexanoate)Ni(II), bis(2,4pentanedionato)Ni(II), and neutral Lewis base adducts thereof.

In one embodiment, the source (starting) material for the nickelcomponent of the liquid mixture comprises hydrolysable nickelcompositions. Hydrolysable nickel precursors are readily soluble in avariety of solvents including common organic solvents and react withmoisture to form Ni(OH)₂, and liberate the anionic ligand in itsprotonated form (e.g., X—H) The ligand imparts solubility in organicsolvents such as aliphatic and aromatic hydrocarbons, ethers, andalcohols and generally affects the reactivity of the nickel complex. Akey functional characteristic of the hydrolysable nickel precursor is toconvert into a nickel hydroxide or oxide when exposed to water vapor atlow temperature (e.g., below 150° C.). Preferred hydrolysable nickelprecursors are prepared using Ni-complexes that are stabilized bysubstituted alkoxide ligands derived from alcohols of the followinggeneral formulae:HOC(R³)(R⁴)C(R⁵)(R⁶)(R⁷)wherein R³, R⁴, R⁵, R⁶, and R⁷ are independently substituted orunsubstituted hydrocarbyl groups, at least one of R³, R⁴, R⁵, R⁶, and R⁷comprises an electronegative heteroatom, and where any of R³, R⁴, R⁵,R⁶, and R⁷ can be joined together to form ring. The preferredelectronegative heteroatoms are oxygen or nitrogen. Preferred alkoxideligands [⁻OC(R³)(R⁴)C(R⁵)(R⁶)(R⁷)] are derived from alcohols in whichone or more R⁵, R⁶, and R⁷ is an ether or amine functional group. Anexemplary alkoxide ligand is the one derived from1-dimethylamino-2-propanol (DMAP): HOCH(Me)CH₂NMe₂. By way of furtherexample, in one embodiment the nickel composition is a hydrolysablenickel composition corresponding to the formula:

In one embodiment, the source (starting) material(s) for the nickelcomponent of the liquid mixture is soluble or dispersible in the liquidmixture and chemically or thermally decomposes to provide a source of atleast one Group 6 metal and/or at least one bleached state stabilizingelement in addition to nickel. For example, in one such embodiment thesource material for the nickel component of the liquid mixture is anorganic-ligand stabilized metal complex or an inorganic salt containingat least one such Group 6 metal and/or at least one such bleached statestabilizing element. For example, the salt may be a halide, nitrate,hydroxide, carbonate, or sulfate salt or an adduct thereof (e.g., acid,ether, amine or water adducts). In one preferred embodiment, the Group 6metal(s) and bleached state stabilizing element(s) is/are selected fromthe group consisting of organic derivatives of Y, Ti, Zr, Hf, V, Nb, Ta,Mo, W, B, Al, Ga, In, Si, Ge, Sn, Sb and combinations thereof. Aspreviously mentioned, a wide variety of organic-ligand stabilizedderivatives of these elements are known in the literature and useful ascomponents of the liquid mixtures of this invention. These include,preferably, of complexes where the stabilizing organic ligands arealkoxides, carboxylates, diketonates, amides. For metals having higheroxidations states such as the Group VI metals, oxo-derivativescomprising anionic organic ligands such as alkoxides are preferredincluding the (RO)₄MO, and (RO)₂MO₂ where M is Mo or W, O is oxygen, andR is a hydrocarbyl, substituted hydrocarbyl, or hydrocarbyl orsubstituted hydrocarbyl silyl group.

In one embodiment, the source (starting) material(s) for the Group 6metal(s) of the liquid mixture comprises a Group 6 metal-containingcomposition that is soluble or dispersible in the liquid mixture andthat chemically or thermally decomposes to provide a source of the Group6 metal(s) for the lithium nickel oxide film that is filterable througha 0.2 micron filter prior to the coating step. For example, in oneembodiment the Group 6 metal source is an organic-ligand stabilizedmetal complex or an inorganic salt. For example, the salt may be ahalide, nitrate, hydroxide, carbonate, or sulfate salt or an adductthereof (e.g., acid, ether, amine or water adducts). As previouslynoted, such as complex(es) may also contain nickel in addition to theGroup 6 metal(s). In one preferred embodiment, the Group 6 metal(s)is/are selected from the group consisting of organic derivatives of Mo,W, and combinations thereof. As previously mentioned, a wide variety oforganic-ligand stabilized derivatives of these elements are known in theliterature and useful as components of the liquid mixtures of thisinvention. These include, preferably, of complexes where the stabilizingorganic ligands are alkoxides, carboxylates, diketonates, amides. In oneembodiment oxo-derivatives comprising anionic organic ligands such asalkoxides are preferred, including, for example, (RO)₄MO, and (RO)₂MO₂where M is Mo or W, O is oxygen, and R is a hydrocarbyl, substitutedhydrocarbyl, or hydrocarbyl or substituted hydrocarbyl silyl group.

In one embodiment, the source (starting) material(s) for the bleachedstate stabilizing element(s) of the liquid mixture comprises a bleachedstate stabilizing element-containing composition that is soluble ordispersible in the liquid mixture and that chemically or thermallydecomposes to provide a source of the bleached state stabilizingelement(s) for the lithium nickel oxide film that is filterable througha 0.2 micron filter prior to the coating step. For example, in oneembodiment the bleached state stabilizing element source is anorganic-ligand stabilized metal complex or an inorganic salt. Forexample, the salt may be a halide, nitrate, hydroxide, carbonate, orsulfate salt or an adduct thereof (e.g., acid, ether, amine or wateradducts). As previously noted, such as complex(es) may also containnickel in addition to the bleached state stabilizing element(s). In onepreferred embodiment, the bleached state stabilizing element(s) is/areselected from the group consisting of organic derivatives of Y, Ti, Zr,Hf, V, Nb, Ta, B, Al, Ga, In, Si, Ge, Sn, Sb and combinations thereof.As previously mentioned, a wide variety of organic-ligand stabilizedderivatives of these elements are known in the literature and useful ascomponents of the liquid mixtures of this invention. These include,preferably, of complexes where the stabilizing organic ligands arealkoxides, carboxylates, diketonates, amides. By way of further example,in one such embodiment, the liquid mixture comprises at least bleachedstate stabilizing element(s) selected from the group consisting of Y,Ti, Zr, Hf, V, Nb, Ta, B, Al, Ga, In, Si, Ge, Sn, Sb and combinationsthereof.

The solvent system may comprise a single solvent or a mixture ofsolvents in which the lithium, nickel and bleached state stabilizingelement(s) are dissolved or dispersed. In embodiment, the solvent systemcomprises a protic solvent including water, and protic organic solventssuch as alcohols, carboxylic acids and mixtures thereof. Exemplaryprotic organic solvents include methanol, ethanol,2,2,2-trifluouroethanol, 1-propanol, 2-propanol, 1-butanol, and2-ethoxyethanol; stearic acid, oleic acid, oleamine, and octadecylamineand the like, and mixtures thereof. In another embodiment, the solventsystem comprises a polar or nonpolar aprotic solvent. For example, inone such embodiment the solvent system may comprise an alkane, andolefin, an aromatic, an ester or an ether solvent or a combinationthereof. Exemplary non-polar aprotic solvents include hexane, octane,1-octadecene, benzene, toluene, xylene, and the like. Exemplary polaraprotic solvents include, for example, N,N-dimethylformamide;1,3-dimethyl-2-imidazolidinone; N-methyl-2-pyrrolidinone; acetonitrile;dimethylsulfoxide; acetone; ethyl acetate; benzyl ether,trioctylphonphine, and trioctylphosphine oxide, and the like, andmixtures thereof. Exemplary ethereal solvents include, for example,diethyl ether, 1,2-dimethoxyethane, methyl-tert-butyl ether,tetrahydrofuran, 1,4-dioxane, and the like, and mixtures thereof.

The liquid mixture may be formed by introducing the lithium, nickel,Group 6 metal and (optional) bleached state stabilizing element sourcematerials into the solvent system at a temperature typically in therange of about 25° C. to 350° C. Depending upon their chemicalcomposition and stability, the lithium, nickel and Group 6 metal sourcematerials may be dissolved or dispersed in the solvent system under aninert atmosphere. In a preferred case the lithium, nickel, and Group 6metal(s) are alkoxides that are hydrolysable, the preferred solvents arealcohols, and the liquid mixture is prepared in an inert atmosphere toprevent hydrolysis and the formation of precipitates prior to the filmdeposition process. In certain other embodiments, however, the lithium,nickel and Group 6 metal source materials may be dissolved or dispersedin the solvent system in air or a synthetic air (N₂/O₂) ambient.Independent of ambient, the sequence in which the lithium, nickel andGroup 6 metal source material(s) are introduced to the solvent system toform the liquid mixture is not narrowly critical. Thus, for example, incertain embodiments they may be combined with each other, or the solventsystem in any sequence. By way of further example, in one embodiment,the lithium, nickel and Group 6 metal source materials for the liquidmixture are three separate, chemically distinct materials. In anotherembodiment, at least one of the source (starting) materials constitutesa source of a combination of at least two of lithium, nickel, and Group6 metal(s), e.g., (i) lithium and nickel, (ii) lithium and a Group 6metal, (iii) nickel and a Group 6 metal, (iv) at least one Group 6 metaland another Group 6 metal or a bleached state stabilizing element or (v)lithium, nickel and at least one Group 6 metal.

The solvent system may also contain a range of additives. For example,the liquid mixture may contain solubility enhancers and complexingagents that stabilize the liquid mixture thermally and hydrolytically,such as organic acids, organic carbonates, and amines and polyethers.The liquid mixture may also contain wetting agents such as propyleneglycol for enhancing the quality of the layers derived from the liquidmixture. In general, simple variation of lithium, nickel, and bleachedstate stabilizing element components in a solvent system will producehomogeneous solutions that can be filtered through a 0.2 micron filterwithout substantial loss of mass or change in the lithium, nickel, Group6 metal(s) and optional bleached state stabilizing element composition.

When the liquid mixture solvent system is aqueous, the use of readilyavailable, water soluble, lithium, bleached state metal, and nickelprecursors may be preferred. Exemplary lithium and nickel precursors inthis embodiment include simple inorganic salts such as the nitrates,hydroxides, and carbonates, or salts of organic acids such as theacetates. Exemplary lithium precursors in this embodiment include simpleinorganic salts such as lithium nitrate and lithium hydroxide or airstable organic salts such as lithium acetate. In certain suchembodiments, lithium acetate is sometimes preferred. Exemplary nickelprecursors in this embodiment include simple inorganic salts such asnickel nitrate, nickel hydroxide, and nickel carbonate; or air stableorganic salts such as nickel acetate or nickel dienoate compounds (e.g.,bis(2-ethylhexanoate)Ni(II)) with nickel acetate being preferred incertain embodiments). Exemplary bleached state metal precursor(s) inthis embodiment include simple inorganic, oxide precursors such as themetal chlorides, alkoxides, peroxos, oxos or salts of organic acids suchas acetic, lactic, citric or oxalic acid or of these inorganic andorganic ligands in combination. For example, when the liquid mixturecomprises tungsten, tungsten (oxo)tetra(isopropoxide) and ammoniummetatungstate can be used with ammonium metatungstate being preferred incertain embodiments. When the liquid mixture comprises titanium,ammonium titanium lactate is preferred in certain embodiments. When theliquid mixture comprises zirconium, zirconyl nitrate and zirconiumacetate hydroxide may be used in certain embodiments with zirconylnitrate being sometimes preferred. When the liquid mixture comprisesniobium, ammonium niobate oxalate or niobium peroxo complexes may beused with peroxo complexes being sometimes preferred.

In some embodiments, the formation of stable solutions of lithium,nickel and other metals may be aided by the use of acids to minimize oreven avoid precipitation when the various lithium, nickel and metalprecursors are combined. Common inorganic acids such as hydrochloric andnitric acid and organic acids such as lactic, citric, and glyoxylic acidmay be used for this purpose with citric acid being preferred in certainembodiments. One of skill in the art will appreciate that certainorganic acids will both lower the pH of the liquid mixture and minimizeprecipitation and that simple variation of the choice and concentrationof organic acid will sometimes lead to acceptable (stable,precipitate-free solutions) and will sometimes lead to non-acceptable(substantial precipitation) liquid mixtures. For example, when glyoxylicacid is used to lower the pH of the solution, a precipitate is oftenformed upon combination with one or more of the liquid mixtureprecursors. In some cases the pH is adjusted to promote the dissolutionof all the metal precursors in the mixture by the addition of base suchas ammonium hydroxide. The pH is preferably not adjusted above the pH atwhich any of the components precipitate from the solution.

When aqueous liquid mixtures are used, the addition of wetting agentadditives is often preferred for improving the film quality of thelithium mixed-metal nickel oxide material. Classes of additives includepolymers such as polyethers or polyols (e.g., polyethylene glycol),alcohols such as ethanol or butanol, esters such as ethyl acetate, aminoalcohols such as N,N-diethylamino ethanol, mixed alcohol ethers such as2-ethoxyethanol, glycols such as propylene glycol with propylene glycolpropyl ether and propylene glycol monomethyl ether acetate typicallybeing selected.

When the liquid mixture solvent system is an organic solvent, a polarorganic solvent such as an alcohol, an ether solvent system, or anon-polar organic solvent such as toluene, hexane may be used. When apolar solvent is used, the use of organometallic complexes of lithium,nickel and other metal precursors is generally preferred. Exemplarylithium, nickel and other metal precursors include hydrolyzablecomplexes such as alkoxides, aminoalkoxides, diolates, or amides thatreadily react to water, converting to hydroxides. Exemplary lithium andnickel precursors include their (N,N-dimethylamino-isopropoxide)complexes. Exemplary Group 4, Group 5, Group 6 and other bleached stateelement precursors include alkoxides, such as ethoxides, isopropoxides,butoxides, oxyalkoxides, or chloroalkoxides that are compatibly solublewith lithium and nickel precursors and preferably with no precipitation.One exemplary method for forming liquid mixtures in a polar organicsolvent, such as an alcohol solvent, comprises combining alkoxidecomplexes of lithium, bleached state metal(s), and nickel between 25 and80 C in an inert atmosphere.

When hydrolysable metal precursors are used, the coating solutions arereadily reactive to moisture in air, resulting in precipitation of theirmetal hydroxides, oxide or carbonates. Therefore, addition of polarorganic solvents that can moderate hydrolysis is sometimes preferredmethod for stabilizing these solutions. Classes of additives includechelating alcohols or amino alcohols such as 2-methoxyethanols,dimethylaminoethanol, or propyl amino ethanols, glycols such aspropylene glycol, or ethylene glycol, low-pKa solvents such ashexafluoropropanol with propylene glycol or propylene carbonate aresometimes preferred.

In accordance with one aspect of the present invention, electrochromicanodic layers may be prepared from the liquid mixtures in a series ofsteps. In general, a film is formed from the liquid mixture on asubstrate, solvent is evaporated from the liquid mixture, and the filmis treated to form the electrochromic anodic layer. In one suchembodiment, the film is thermally treated to form the electrochromicanodic layer.

The liquid mixture may be deposited onto any substrate having suitableoptical, electrical, thermal, and mechanical properties. Such substratesinclude, for example, glass, plastic, metal, and metal coated glass orplastic. Non-exclusive examples of possible plastic substrates arepolycarbonates, polyacrylics, polyurethanes, urethane carbonatecopolymers, polysulfones, polyimides, polyacrylates, polyethers,polyester, polyethylenes, polyalkenes, polyimides, polysulfides,polyvinylacetates and cellulose-based polymers. If a plastic substrateis used, it may be barrier protected and abrasion protected using a hardcoat of, for example, a diamond-like protection coating, asilica/silicone anti-abrasion coating, or the like, such as is wellknown in the plastic glazing art. Suitable glasses include either clearor tinted soda lime glass, chemically tempered soda lime glass, heatstrengthened soda lime glass, tempered glass, or borosilicate glass.

In one embodiment, the substrate comprises a transparent conductivelayer (as described in connection with FIG. 1) on glass, plastic, metal,and metal coated glass or plastic. In this embodiment, the liquidmixture may be deposited directly onto the surface of the transparentconductive layer.

In another embodiment, the substrate comprises a current modulatinglayer (as described in connection with FIG. 2) on glass, plastic, metal,and metal coated glass or plastic. In this embodiment, the liquidmixture may be deposited directly onto the surface of the currentmodulating layer.

In another embodiment, the substrate comprises a ion conductor layer (asdescribed in connection with FIG. 1) on glass, plastic, metal, and metalcoated glass or plastic. In this embodiment, the liquid mixture may bedeposited directly onto the surface of the ion conductor layer.

A range of techniques may be used to form a layer that is derived fromthe liquid mixture on the substrate. In one exemplary embodiment, acontinuous liquid layer of the liquid mixture is applied to thesubstrate by meniscus coating, roll coating, dip coating, spin coating,screen printing, spray coating, ink jet coating, knife over roll coating(gap coating), metering rod coating, curtain coating, air knife coating,and partial immersion coating and like, and solvent is then removed.Alternatively, the layer may be formed by directing droplets of theliquid mixture toward the substrate by spray or ink jet coating, andremoving solvent. Regardless of technique, a layer is formed on thesubstrate containing lithium, nickel and at least one Group 6 metal inthe ratios previously described herein in connection with theelectrochromic lithium nickel oxide layers. That is, the relativeamounts of lithium, nickel, molybdenum and tungsten in the layer arecontrolled such that an atomic ratio of lithium to the combined amountof nickel and Group 6 metal(s) and the atomic ratio of the combinedamount of all Group 6 metal(s) to nickel is as previously described.

In those embodiments in which the lithium composition, nickelcomposition and/or Group 6 metal (and optional bleached statestabilizing element) composition(s) are hydrolysable, it may bedesirable to form the layer on the substrate in a controlled atmosphere.For example, in one embodiment, deposition of the liquid mixture occursin an atmosphere having a relative humidity (RH) of less than 55% RH. Byway of further example, in one such embodiment, deposition of the liquidmixture occurs in an atmosphere having a relative humidity not in excessof 40% RH By way of further example, in one such embodiment, depositionof the liquid mixture occurs in an atmosphere having a relative humiditynot in excess of 30% RH. By way of further example, in one suchembodiment, deposition of the liquid mixture occurs in an atmospherehaving a relative humidity not in excess of 20% RH. By way of furtherexample, in one such embodiment, deposition of the liquid mixture occursin an atmosphere having a relative humidity not in excess of 10% RH oreven not in excess of 5% RH. In some embodiments, the atmosphere may beeven drier; for example, in some embodiments, deposition may occur in adry atmosphere defined by a RH of less than 5% RH, less than 1% RH, oreven less than 10 ppm water.

The deposition of the liquid mixture onto the substrate may be carriedout in a range of atmospheres. In one embodiment, the liquid mixture isdeposited in an inert atmosphere (e.g., nitrogen or argon) atmosphere.In an alternative embodiment, the liquid mixture is deposited in anoxygen-containing atmosphere such as compressed dry air or synthetic air(consisting of a mixture of oxygen and nitrogen in approximately 20:80v/v ratio). In certain embodiments, for example, when the liquid mixturecomprises a hydrolysable precursor for the lithium, nickel, and/or Group6 metal(s), performance may be improved by minimizing the liquidmixture's and the deposited film's exposure to CO₂. For example, in someembodiments the ambient may have a CO₂ concentration of less than 50ppm, less than 5 ppm or even less than 1 ppm.

The temperature at which the liquid mixture is deposited onto thesubstrate may range from near room temperature to elevated temperatures.For spray coating, for example, the maximum high temperature would belimited by the substrate stability (e.g., 550 to 700° C. for glass, lessthan 250° C. for most plastics, etc.) and the desired annealingtemperature for the layer. For coating techniques in which a continuousliquid film is applied to a substrate, for example, coating temperatureswill typically be in range of room temperature 25° C. to about 80° C.

After the substrate is coated with the liquid mixture, the resultingfilms may be placed under an air stream, vacuum, or heated to achievefurther drying in order to remove residual solvent. The composition ofthe ambient atmosphere for this step may be controlled as previouslydescribed in connection with the coating step. For example, theatmosphere may have a relative humidity of less than 1% to 55% RH, itmay be an inert atmosphere (nitrogen or argon), or it may containoxygen.

In those embodiments in which the liquid mixture contains a hydrolysableprecursor for the lithium, nickel, or Group 6 metal, the coatedsubstrate may then be exposed to a humid atmosphere (e.g., a RH of atleast 30% RH) to hydrolyze the metal complex(es) to form a protonatedligand bi-product and a lithium nickel polyhydroxide film. Such exposuremay be carried out, for example, at a temperature in the range about 40°C. to about 200° C. for a period of about 5 minutes to about 4 hours. Insome embodiments, a second thermal processing step at temperatures above200° C., preferably above 250° C., to form an oxide film havingsubstantially lower levels of hydroxide content.

In one embodiment, the coated substrate is heat-treated (annealed) toform the electrochromic lithium nickel oxide layer. Depending upon thecomposition of the liquid mixture and the substrate stability, thecoated substrate is annealed at a temperature of at least about 200° C.For example, in one embodiment the substrate may be annealed at atemperature at the lower end of this range, e.g., at least about 250° C.but less than about 700° C.; temperatures within this range would beparticularly advantageous for polymeric substrates that may losedimensional stability at greater temperatures. In other embodiments, thecoated substrate may be annealed at a temperature in the range about300° C. to about 650° C. By way of further example, in one suchembodiment the coated substrate may be annealed at a temperature in therange of about 350° C. to about 500° C. In general, however, annealingtemperatures will typically not exceed about 750° C. The anneal time mayrange from several minutes (e.g., about 5 minutes) to several hours.Typically, the anneal time will range from about 30 minutes to about 2hours. Additionally, the annealing temperature may be achieved (i.e.,the ramp rate from room temperature to the annealing temperature) over aperiod ranging from 1 minute to about several hours.

In some embodiments it may be desirable to heat-treat the coatedsubstrate in a controlled atmosphere. For example, in one embodiment,the coated substrate is annealed in an atmosphere having a relativehumidity (RH) of about 5% to 55% RH. By way of further example, in onesuch embodiment, the coated substrate is annealed in an atmospherehaving a relative humidity not in excess of 10% RH or even not in excessof 5% RH. In some embodiments, the atmosphere may be even drier; forexample, in some embodiments, the coated substrate is annealed in a dryatmosphere defined by a RH of less than 5% RH, less than 1% RH, or evenless than 10 ppm water.

In some embodiments, the composition of the carrier gas in which theheat-treatment is carried out may be an inert (e.g., nitrogen or argon)atmosphere. Alternatively, it may contain oxygen (e.g., compressed dryair or synthetic air consisting of a mixture of oxygen and nitrogen inapproximately 20:80 v/v ratio) environment. In certain embodiments,performance may be improved by reducing the exposure to CO₂ usingatmospheres in which the CO₂ concentration is less than 50 ppm. Forexample, in some embodiments the CO₂ concentration may be less than 5ppm or even less than 1 ppm.

The coated substrate may be heat-treated (annealed) by various means. Inone embodiment, the coated substrate is heat-treated (annealed) in arapid thermal annealer in which heating occurs primarily throughabsorption of radiative energy by the layer and/or the substrate. Inanother embodiment, the coated substrate is heat-treated (annealed) in abelt furnace in which heating occurs in one or more zones in acontinuous process. In another embodiment, the coated substrate isheat-treated (annealed) in a convection oven and furnaces in whichheating is achieved in a batch process by a combination of radiative andconductive processes. In another embodiment, the coated substrate isheat-treated (annealed) using a hot plate (bake plate) or surfaceheating where heating occurs primarily by conduction by placing thesubstrate on or slightly above a heated surface; examples includeproximity baking where the sample is held above a plate using a cushionof air, hard contact baking where the substrate is held to the surfaceof a heated surface via vacuum or some other method, and soft contactbaking where the substrate rests on a heated surface via gravity alone.

In some embodiments, the resulting anodic electrochromic lithium nickeloxide layer has an average thickness between about 25 nm and about 2,000nm. For example, in one such embodiment the anodic electrochromiclithium nickel oxide layer has a thickness of about 50 nm to about 2,000nm. By way of further example, in one such embodiment the anodicelectrochromic lithium nickel oxide layer has a thickness of about 25 nmto about 1,000 nm. By way of further example, in one such embodiment,the anodic electrochromic lithium nickel oxide layer has an averagethickness between about 100 nm and about 700 nm. In some embodiments,the anodic electrochromic lithium nickel oxide layer has a thickness ofabout 250 nm to about 500 nm.

Depending upon the method of deposition and the solvent system comprisedby the liquid mixture, the resulting anodic electrochromic nickel oxidelayer may comprise a significant amount of carbon. For example, in oneembodiment, the anodic electrochromic nickel oxide material contains atleast about 0.01 wt % carbon. By way of further example, in oneembodiment the anodic electrochromic nickel oxide material contains atleast about 0.05 wt. % carbon. By way of further example, in oneembodiment the anodic electrochromic nickel oxide material contains atleast about 0.1 wt. % carbon. By way of further example, in one anodicembodiment the electrochromic nickel oxide material contains at leastabout 0.25 wt. % carbon. By way of further example, in one embodimentthe anodic electrochromic nickel oxide material contains at least about0.5 wt. % carbon. Typically, however, the anodic electrochromic nickeloxide material will generally contain no more than about 5 wt % carbon.Thus, for example, in one embodiment, the anodic electrochromic nickeloxide material will contain less than 4 wt % carbon. By way of furtherexample, in one embodiment the anodic electrochromic nickel oxidematerial will contain less than 3 wt. % carbon. By way of furtherexample, in one embodiment the anodic electrochromic nickel oxidematerial will contain less than 2 wt. % carbon. By way of furtherexample, in one embodiment the anodic electrochromic nickel oxidematerial will contain less than 3 wt. % carbon. Thus, in certainembodiments, the anodic electrochromic nickel oxide material may contain0.01 wt. % to 5 wt. % carbon. By way of further example, in certainembodiments, the anodic electrochromic nickel oxide material may contain0.05 wt. % to 2.5 wt. % carbon. By way of further example, in certainembodiments, the anodic electrochromic nickel oxide material may contain0.1 wt. % to 2 wt. % carbon. By way of further example, in certainembodiments, the anodic electrochromic nickel oxide material may contain0.5 wt. % to 1 wt. % carbon.

EXAMPLES

The following non-limiting examples are provided to further illustratethe present invention. It should be appreciated by those of skill in theart that the techniques disclosed in the examples that follow representapproaches the inventors have found function well in the practice of theinvention, and thus can be considered to constitute examples of modesfor its practice. However, those of skill in the art should, in light ofthe present disclosure, appreciate that many changes can be made in thespecific embodiments that are disclosed and still obtain a like orsimilar result without departing from the spirit and scope of theinvention.

Example 1 Synthesis of Hydrolysable Ni Precursor

Hydrolysable Ni(II) precursor compound (Ni(DMAP)₂) has been synthesizedby a modification of the known method (Hubert-Pfalzgraf et. al.Polyhedron, 16 (1997) 4197-4203.) To an anhydrous toluene solution (200mL) of pre-dried N,N-dimethylamino-2-propanol (8.17 g, 0.0787 mol), wasadded NaH (1.92 g, 0.0800 mol) by small portions in a N₂-purged glovebox. The mixture was stirred at room temperature for 2 h until it becameclear. To this solution was added Ni(NH₃)₆Cl₂ (9.0 g, 0.039 mol), and itwas heated at 80° C. for 6 h, affording a dark green solution. Then thesolution was evaporated to dryness under reduced pressure, and theresulting solid was re-dissolved in THF (˜300 mL) which then wasfiltered through a gravity funnel. Dark green filtrate solution wasconcentrated to ⅓ of the initial volume, diluted with Hexanes (50 mL)and then cooled in a freezer (−20° C.). Green needle-shape microcrystalswere obtained after one day, which were filtered, and washed with coldHexanes. Yield 80%. Microanalysis of the crystalline compound is shownin Table 1.

TABLE 1 Microanalysis data for NiDMAP compound Formula Calculated FoundNiDMAP C, 45.67 C, 45.91 (NiC₁₀H₂₄N₂O₂) H,  9.20 H,  9.32 N, 10.65 N,10.78

Example 2 LiNiO₂ Film Synthesis

In a 20 mL-scintillated vial, were added NiDMAP (70 mg), LiOMe (11 mg)and anhydrous MeOH (0.6 mL), affording a dark red solution. Then,electrically conductive FTO (fluorinated tin oxide, 20 mm×20 mm×2 mm)coated glass was loaded in a spin-coater in the glove box. Onto the FTOsubstrate, was dispensed 0.3 mL of the precursor solution through a 0.2μm filter and spun at 2500 rpm for 1 min. Sealed in a container in orderto avoid air-exposure (CO₂ and moisture), the coated film was taken outof the box and was hydrolyzed under warm moisture (45° C.) for 1 h in aN₂-filled glove bag. Then it was transferred into an O₂-purged tubefurnace and subsequently dehydrated under O₂ at 400° C. for 1 h. Afterbeing cooled down, film thickness was measured as 70 nm by profilometry.Structural phase of the coated film was determined by thin-film XRDmeasurement, which was identified as hexagonal layered LiNiO₂ phaseexhibiting an intense peak at 28=18.79° corresponding to (003)reflection (FIG. 3). Then the film was brought into an Ar-filled glovebox, and its electrochromic property was examined in a combinedelectrochemical/optical setup consisting of a three electrode cell in acuvette placed in the path of a light source and spectrometer. Data wereobtained by cyclovoltammetry with a scan rate 10 mV/s between 1.1 and4.0 V vs Li/Li⁺ in an electrolyte of 1M LiClO₄ in propylene carbonate.Separate pieces of lithium metal were used as the reference and counterelectrodes and optical data were recorded every 1-5 s. The coatingshowed reversible change in optical transmission at 550 nm from 72% to16% in 1.1-4.0 V vs Li/Li⁺, with charge capacity of 30 mC/cm² and CE(coloration efficiency) of 22 cm²/C (FIG. 4). When the Ni and Liprecursor solution was doubly concentrated, a thicker (100 nm) film hasbeen obtained and its reversible CV features remained consistent overthe 100 cycles of voltage sweeping affording a high charge capacity (40mC/cm²). It took a few minutes to get full transmission change between77% and 9% under fixed voltages which resulted CE of 23 cm²/C. Thematerial bleached to within 95% of its most transparent state at 1.55 Vvs. Li/Li⁺.

Example 3 Li₂NiO₂ Clear Film Synthesis

In order to isolate the clear state Li₂NiO₂, a LiNiO₂ film (100 nmthick) prepared as described in Example 2, was electrochemically reducedby cycling between 1.1 and 4.0 V in the electrochemical cell underAr-atmosphere and stopping at 1.1 V. Then, the film was taken out of theAr-box, and was exposed to air while its thin-film XRD was collected byBruker d8 Advance. After that, the film was brought back into theAr-glove box, and EC cycling was carried out, which gave result innegligible current flow with no optical transmission change at 550 nm.

Then, another LiNiO₂ film was prepared in the same method as Example 2,and was cycled 5 times between 1.1 and 4.0 V in the electrochemical cellunder Ar-atmosphere, affording charge capacity estimated to 23 mC/cm².The cycling was stopped at 3.6 V, and the film was isolated andsubsequently immersed in a freshly-prepared solution of LithiumBenzophenone in THF (deep blue solution) without exposure to air. After2 days, the film became clear, and its cyclic voltammograms wererecorded, affording an identical current flow with its previous LiNiO₂phase between 1.1-4.0 V in the electrochemical cell under Ar-atmosphere.Charge capacity is estimated to 25 mC/cm² (see FIG. 5).

Examples 4 Through 13 Li_(x)M_(y)Ni_(1-y)O, Anode Films with VariousCompositions

The coating solutions of Li_(x)M_(y)Ni_(1-y)O_(z) were prepared bydissolving weighed amounts of LiDMAP, NiDMAP and a precursor compound ofbleach state stabilizing metal, M in 1-BuOH, with the various molarratios as presented in Table 2, where z is generally believed to be inthe range of 1.3 and 3.8. Combined solution molarity of the metal ions[Li+M+Ni] was in the range of 1.8-2.8 M. After filtering the solutionsthrough a 0.2 μm filter, they were spun onto FTO substrates under a N₂atmosphere. The resulting coatings were humidified under 40% RH CDA atroom temperature, subsequently calcined for 1 h under the sameatmosphere at 400-550° C. temperature range unless otherwise noted.

After being cooled, the films were brought into an Ar-filled glove box,and the electrochromic properties were examined in a combinedelectrochemical/optical setup consisting of a three electrode cell in acuvette placed in the path of a white light source and spectrometer.Data were obtained by sequential oxidation and reduction undergalvanostatic control followed by constant voltage hold (CC-CV). Theelectrolyte was 1 M LiClO₄ in propylene carbonate. Typically voltageranges of 1.5-4.2, 2.5-4.2 or 2.5-4.0 V vs Li/Li⁺ were applied. Separatepieces of lithium metal were used as the reference and counterelectrodes. Optical data were recorded every 1-5 s. ColorationEfficiency was calculated from the transmission data (at 550 nm) and theamount of charges passed during the second reduction event of the filmover the applied voltage range.

Thin-film X-ray diffraction (XRD) was measured by Bruker D8 Advancediffractometer. Incident beam angles were adjusted to 0.05-0.1° toafford high peak intensity of anode oxide film. Carbon concentration ofthe calcined films was measured and analyzed by SIMS analysis (SecondaryIon Mass Spectrometry) in the Evans Analytical Group. Metal compositionof lithium nickel oxide films was analyzed by digesting the films inhydrochloric acid (Ba internal standard) and performing ICP-OES(Inductively-coupled plasma optical emission spectroscopy, ThermoElectron Iris Intrepid II XPS) analysis.

Film thickness was measured by profilometer and was in the range of125-306 nm for all films shown in Table 2. Measured charge capacity datawere in the range of 3-28 mC/cm² over the applied voltage range, and thefilms switched from a bleached state transmission in the range of 42-87%to a dark state transmission in the range of 14-58% (at 550 nm).Absolute coloration efficiency was in the range of 22-35 cm²/C for allthe films in Table 2. Bleached state voltages for selected films areshown in Table 3. Thin-film XRD data for selected films are listed inTable 4, and their typical XRD patterns are shown in FIG. 6. Carbonconcentration of the calcined films measured and analyzed by SIMSthin-film analysis are shown in Table 5. Metal compositions analyzed byICP are shown in Table 6.

TABLE 2 Various compositions of Li_(x)M_(y)Ni_(1−y)O_(z) anode filmswhere M is among group(VI) metals. Example Precursor No. Metal compoundLi (x) Ni (1 − y) M (y) 4 Mo MoO(OMe)4 1 0.75 0.25 5 Mo MoO(OMe)4 1.330.67 0.33 6 W W(OEt)6 0.49 0.66 0.34 7 W W(OEt)6 0.82 0.82 0.18 8 WW(OEt)6 1.33 0.67 0.33 9 W W(OEt)6 2.16 0.68 0.32 10 W WO(OiPr)4 1.0 0.80.3 11 W WO(OiPr)4 1.13 0.72 0.28 12 W WO(OiPr)4 1.0 0.75 0.25 13 WWO(OiPr)4 1.0 0.1 0.9

TABLE 3 Bleached state voltage observed for variousLi_(x)Ni_(1−y)M_(y)O_(z) anode films. Bleached state Example No.Composition voltage (V vs Li) 6 Li_(0.49)W_(0.34)Ni_(0.66) 3.56 7Li_(0.82)W_(0.18)Ni_(0.82) 2.876 8 Li_(1.33)W_(0.33)Ni_(0.67) 2.88 9Li_(2.16)W_(0.32)Ni_(0.68) 3.113

TABLE 4 Thin-film XRD diffractions for selected Li_(x)M_(y)Ni_(1−y)O_(z)anode films. Example no. Composition 2θ (below 50°)* 13Li₁W_(0.1)Ni_(0.9) 18.7, 37.7, 43.7 12 Li₁W_(0.25)Ni_(0.75) 18.9, 37.7,43.8 *XRD diffraction peaks of Li₂CO₃ and FTO substrates are omittedfrom the 2θ list.

TABLE 5 Measured carbon concentration in the calcinedLi_(x)Ni_(1−y)M_(y)O_(z) films. Carbon concentration Estimated Carboncontent Composition (atoms/cm3) in the oxide film (wt %)*Li_(1.33)W_(0.33)Ni_(0.67) 6E+21 2-3 *Atomic density of metal oxide filmwas assumed as the range of 4-7 g/cm³ based on crystal density of bulkmetal oxides at 25° C.

TABLE 6 Metal composition of the calcinedLi_(1.33)Ni_(0.72)W_(0.28)O_(z) film analyzed by ICP-OES analysis. MetalFormulated Measured component values values Li 1.13 1.11(3) Ni 0.720.71(0) W 0.28 0.29(0)

Examples 14 Through 39 Li_(x)Ni_(1-y-y′)M_(y)M′_(y′)O_(z) Anode Filmswith Various Compositions

Coating solutions of Li_(x)Ni_(1-y)M_(y)M′O_(z) were prepared bydissolving weighed amounts of LiDMAP, NiDMAP, M and M′ precursorcompounds in 1-BuOH, with the various molar ratios between the metals aspresented in Table 7. The solutions were spun and thermally processed inthe same method as in Examples 4-13. After being cooled, the films werebrought into an Ar-filled glove box, and the electrochromic performancewas measured in the same method as described in Examples 4-13.

Film thickness was measured by profilometer, giving the measured valuesin the range of 121-312 nm for all films shown in Table 7. Measuredcharge capacity data were found in the range of 12-29 mC/cm² at thegiven voltage range, and the films switched from a bleached statetransmission in the range of 78-91% to a dark state transmission in therange of 15-41% (at 550 nm). Absolute coloration efficiency was in therange of 20-31 cm²/C for all the films in Table 7.

TABLE 7 Various compositions of Li_(x)Ni_(1−y−y′)M_(y)M′_(y′)O_(z) anodefilms where M is among group(VI) metals. Example No. M M′ Li (x) Ni(1−y−y′) M (y) M′ (y′) 14 W Ti 1.11 0.71 0.27 0.02 15 W Ti 1.07 0.680.27 0.05 16 W Ti 1.04 0.66 0.25 0.09 17 W Zr 1.11 0.71 0.27 0.02 18 WZr 1.07 0.68 0.27 0.05 19 W Zr 1.04 0.66 0.25 0.09 20 W Zr 0.94 0.600.23 0.17 21 W Hf 1.11 0.71 0.27 0.02 22 W Hf 1.07 0.68 0.27 0.05 23 WHf 1.04 0.66 0.25 0.09 24 W Hf 0.94 0.60 0.23 0.17 25 W Ta 1.11 0.710.27 0.02 26 W Ta 1.07 0.68 0.27 0.05 27 W Ta 1.04 0.66 0.25 0.09 28 WTa 0.94 0.60 0.23 0.17 29 W Nb 1.11 0.71 0.27 0.02 30 W Nb 1.07 0.680.27 0.05 31 W Nb 1.04 0.66 0.25 0.09 32 W Nb 0.94 0.60 0.23 0.17 33 WAl 1.11 0.71 0.27 0.02 34 W Al 1.07 0.68 0.27 0.05 35 W Al 1.04 0.660.25 0.09 36 W Si 1.11 0.71 0.27 0.02 37 W Si 1.07 0.68 0.27 0.05 38 WSi 1.04 0.66 0.25 0.09 39 W Si 0.94 0.60 0.23 0.17

Examples 40 Through 43 Li_(x)Ni_(1-y-y′-y″)M_(y)M′_(y′)M″_(y″)O_(z) andLi_(x)Ni_(1-y-y′-y″y′″)M_(y)M′_(y′)M″_(y″)M′″_(y′″)O_(z) Anode Filmswith Various Compositions

Solution preparation, spin-coating and thermal processing methods forLi_(x)Ni_(1-y-y′-y″)M_(y)M′_(y′)M″_(y″)O_(z) anode films are same asExample 4-13, with the molar ratios of each metal component presented inTable 8. Electrochemical and optical measurements also were performed inthe same methods as described in Examples 4-13.

Film thickness was measured by profilometer, giving the measured valuesin the range of 190-277 nm for all the films ofLi_(x)Ni_(1-y-y′-y″)M_(y)M′_(y′)M″_(y″)O_(z) shown in Table 8. Measuredcharge capacity data were found in the range of 3.2-21 mC/cm² at thegiven voltage range, and the films switched from a bleached statetransmission in the range of 73-82% to a dark state transmission in therange of 24-64% (at 550 nm). Absolute coloration efficiency was in therange of 20-25 cm²/C for all the films in Table 8.

TABLE 8 Various compositions ofLi_(x)Ni_(1−y−y′−y″)M_(y)M′_(y′)M″_(y″)O_(z) anode films where M and M′are among group(VI) metals. Example No. M M′ M″ Li (x) Ni (1−y−y′−y″) M(y) M′ (y′) M″(y″) 40 W Mo — 1.30 0.67 0.30 0.03 0.00 41 W Mo Nb 1.260.65 0.29 0.03 0.03 42 W Mo Zr 1.26 0.65 0.29 0.03 0.03 43 W Mo Al 1.260.65 0.29 0.03 0.03

Examples 44 Device Assembled by WO₃ Cathode andLi_(1.262)W_(0.291)Mo_(0.0291)Ni_(0.651)Zr_(0.0291) Anode Film

Five layer device was assembled using fully calcinedLi_(1.262)W_(0.291)Mo_(0.0291)Ni_(0.651)Zr_(0.0291) anode film on FTOsubstrate (active area ˜90 mm2) and tungsten oxide based cathode,prepared on FTO substrate via known procedures (active area from ˜90 to260 mm2). In an inert glove box, the cathode containing substrate wasplaced on a preheated hotplate set to 90° C. and 175 uL of anelectrolyte precursor solution was deposited onto the surface. Theelectrolyte precursor solution consisted of 3 parts by weight 25%poly(methyl methacrylate) in dimethylcarbonate to one part by weight 1Mlithium bis(trifluoromethylsulfonyl)imide in propylene carbonate. Theelectrolyte precursor solution on the cathode substrate was allowed todry for 15 min and then, near the edge of the substrate, 4 polyimideshims of 100 microns thickness and ˜2 mm width were placed such thatthey were above the substrate surface protruding in ˜2 mm. The anodecontaining substrate was then placed upon the electrolyte with anoverlap of ˜260 mm2 relative to the cathode containing substrate. Theentire assembly was laminated at 90° C. for 10 min under vacuum at apressure of ˜1 atm. After lamination, the shims were removed andcontacts were applied to each electrode substrate using metal clips. Theassembled device was then transferred into an encapsulation fixture andencapsulated with epoxy (Loctite E-30CL) such that only the contacts andan optical window remain unencapsulated. After the encapsulant hardened(˜16 hrs) the device was measured in a two electrode electrochemicalsetup combined with an optical light source and spectrometer. Data wereobtained by sequential oxidation and reduction under potentiostaticcontrol cycling voltage between 11 and −0.9 V, the anode being connectedto the positive lead at 25° C. Cycles were switched when the absoluteresidual current fell below 5 microamps. Optical data were recordedevery 1-5 s. The device switched from a bleached state transmission of71% to a dark state transmission of 4.7% (at 550 nm), exhibiting Q of 17mC/cm² after 10 cycles.

What is claimed is:
 1. A multi-layer electrochromic structure comprisinga first substrate and an anodic electrochromic layer comprising alithium nickel oxide composition on the first substrate, the anodicelectrochromic layer containing lithium, nickel, and at least one Group6 metal selected from the group consisting of molybdenum and tungsten,wherein (i) the atomic ratio of lithium to the combined amount of nickeland such Group 6 metal(s) in the anodic electrochromic layer is at least0.4:1, respectively, (ii) the atomic ratio of the amount of such Group 6metal(s) to the combined amount of nickel and such Group 6 metal(s) inthe anodic electrochromic layer is at least about 0.025:1, respectively,and (iii) the anodic electrochromic layer exhibits a largest interplanardistance (d-spacing) of at least 2.75 Å as measured by X-ray diffraction(XRD).
 2. The multi-layer electrochromic structure of claim 1, whereinthe anodic electrochromic layer has a coloration efficiency absolutevalue of at least 19 cm²/C.
 3. The multi-layer electrochromic structureof claim 1 wherein the anodic electrochromic layer comprises tungsten.4. The multi-layer electrochromic structure of claim 3 wherein (i) theatomic ratio of lithium to the combined amount of nickel and tungsten inthe anodic electrochromic layer is at least 0.4:1, respectively, and(ii) the atomic ratio of the amount of tungsten to the combined amountof nickel and tungsten in the anodic electrochromic layer is about0.025:1 to about 0.8:1, respectively.
 5. The multi-layer electrochromicstructure of claim 4 wherein the atomic ratio of lithium to the combinedamount of nickel and tungsten in the anodic electrochromic layer is inthe range about 0.7:1 to about 1.5:1, respectively.
 6. The multi-layerelectrochromic structure of claim 4 wherein the atomic ratio of tungstento the combined amount of nickel and tungsten in the anodicelectrochromic layer is in the range of about 0.1:1 and about 0.6:1,respectively.
 7. The multi-layer electrochromic structure of claim 1wherein the anodic electrochromic layer comprises molybdenum.
 8. Themulti-layer electrochromic structure of claim 7 wherein (i) the atomicratio of lithium to the combined amount of nickel and molybdenum in theanodic electrochromic layer is at least 0.4:1, respectively, and (ii)the atomic ratio of the amount of molybdenum to the combined amount ofnickel and molybdenum in the anodic electrochromic layer is about0.025:1 to about 0.8:1, respectively.
 9. The multi-layer electrochromicstructure of claim 8 wherein the atomic ratio of lithium to the combinedamount of nickel and molybdenum in the anodic electrochromic layer is inthe range about 0.75:1 to about 3:1, respectively.
 10. The multi-layerelectrochromic structure of claim 8 wherein the atomic ratio ofmolybdenum to the combined amount of nickel and molybdenum in the anodicelectrochromic layer is in the range of about 0.1:1 and about 0.6:1,respectively.
 11. The multi-layer electrochromic structure of claim 1wherein (i) the atomic ratio of lithium to the combined amount ofnickel, tungsten, and molybdenum in the anodic electrochromic layer isat least 0.4:1, respectively, and (ii) the atomic ratio of the combinedamount of tungsten and molybdenum to the combined amount of nickel,tungsten and molybdenum in the anodic electrochromic layer is about0.025:1 to about 0.8:1, respectively.
 12. The multi-layer electrochromicstructure of claim 11 wherein (i) the anodic electrochromic layercomprises at least one bleached state stabilizing element selected fromthe group consisting of Y, Ti, Zr, Hf, V, Nb, Ta, B, Al, Ga, In, Si, Ge,Sn, P, and Sb, (ii) the atomic ratio of lithium to the combined amountof nickel, tungsten, molybdenum and the bleached state stabilizingelement(s) in the anodic electrochromic layer is at least 0.4:1,respectively, and (iii) the atomic ratio of the combined amount oftungsten, molybdenum and the bleached state stabilizing element(s) tothe combined amount of nickel, tungsten, molybdenum and the bleachedstate stabilizing elements in the anodic electrochromic layer is about0.025:1 to about 0.8:1, respectively.
 13. The multi-layer electrochromicstructure of claim 12 wherein the anodic electrochromic layer has anaverage thickness between about 25 nm and about 2,000 nm.
 14. Themulti-layer electrochromic structure of claim 12 wherein the firstsubstrate comprises glass, plastic, metal, or metal-coated glass orplastic.
 15. The multi-layer electrochromic structure of claim 12wherein the anodic electrochromic layer comprises at least 0.05 wt. %carbon.
 16. The multi-layer electrochromic structure of claim 12 whereinthe anodic electrochromic layer has a coloration efficiency absolutevalue of at least about 19 cm²/C.
 17. The multi-layer electrochromicstructure of claim 12 wherein the anodic electrochromic layer has ableached state voltage of at least 2V.
 18. The multi-layerelectrochromic structure of claim 1 wherein the multi-layerelectrochromic structure further comprises a first electricallyconductive oxide layer and the first electrically conductive oxide layeris between the anodic electrochromic layer and the first substrate. 19.A multi-layer electrochromic structure of claim 18 wherein themulti-layer electrochromic structure further comprises a secondsubstrate, a second electrically conductive layer, a cathode layer, andan ion conductor layer, wherein the anodic electrochromic layer isbetween the first electrically conductive layer and the ion conductorlayer, the second electrically conductive layer is between the cathodelayer and the second substrate, the cathode layer is between the secondelectrically conductive layer and the ion conductor layer, and the ionconductor layer is between the cathode layer and the anodicelectrochromic layer.
 20. The multi-layer electrochromic structure ofclaim 1 wherein the anodic electrochromic layer exhibits long rangeordering as measured by the presence of at least one reflection peak inthe XRD pattern below 26 degrees (20) when measured with copper Kαradiation.
 21. The multi-layer electrochromic structure of claim 1wherein the anodic electrochromic layer comprises at least 0.05 wt. %carbon.
 22. The multi-layer electrochromic structure of claim 1 whereinthe anodic electrochromic layer has a coloration efficiency absolutevalue of at least about 19 cm²/C.
 23. The multi-layer electrochromicstructure of claim 1 wherein the anodic electrochromic layer has ableached state voltage of at least 2V.
 24. A multi-layer electrochromicstructure comprising a first substrate and an anodic electrochromiclayer comprising a lithium nickel oxide composition on the firstsubstrate, the anodic electrochromic layer containing lithium, nickel,and at least one Group 6 metal selected from the group consisting ofmolybdenum and tungsten, wherein (i) the atomic ratio of lithium to thecombined amount of nickel and such Group 6 metal(s) in the anodicelectrochromic layer is at least 0.4:1, respectively, (ii) the atomicratio of the amount of such Group 6 metal(s) to the combined amount ofnickel and such Group 6 metal(s) in the anodic electrochromic layer isat least about 0.025:1, respectively, and (iii) the anodicelectrochromic layer comprises at least 0.05 wt. % carbon.